1974 MAY University State . GI-418340 No. Grant Under Oregon (RANN) Needs National to Applied Research Foundation, Science National the by Supported 1- Lissaman S. B. Peter And Wilson E. Robert MACHINES POWER WIND Of AERODYNAMICS APPLIED 1974 July, California Pasadena, Inc. Aerovironment, Lissaman S. B. Peter and 97331 Oregon Corvallis, University State Oregon Wilson E. Robert by MACHINES POWER WIND OF AERODYNAMICS APPLIED 79 74 73 73 69 64 61 Relations Approximate Gradient Wind Vertical of Effects The Introduction GRADIENT WIND VERTICAL TO DUE MOMENTS AND FORCES 6, CHAPTER Rotor Circular The Rotor Darrieus Wake the of Modeling Vortex Theory Vortex Glauert Rotor; Optimum The Models Loss Tip Equations Flow Annulus Wake the of Representation Vortex 59 54 49 44 39 MACHINES AXIS CROSS-WIND 5, CHAPTER 61 39 34 25 20 17 17 12 11 11 8 7 6 6 THEORY VORTEX/STRIP ROTORS; AXIS WIND 4, CHAPTER Actuators Ducted States Flow Multiple of Model Simple Rotation Wake of Effect Theory Rankine-Froude THEORY MOMENTUM GENERAL ROTORS; AXIS WIND 3, CHAPTER Translators Lifting Translators Drag MACHINES POWER WIND TRANSLATING 2, CHAPTER Rotor Circulation-Controlled Design Smith-Putnam Rotor Ducted Machines Axis - Wind Power Wind in Aerodynamics of Role 2 Rotor Darrieus Rotor Madaras Rotor Savonius Machines Cross-Wind-Axis 3 5 4 3 1 INTRODUCTION 1, CHAPTER page CONTENTS OF TABLE 107 FACTORS "F" THE OF USE II, APPENDIX REFERENCES 85 SYMBOLS 87 INSTRUCTIONS OPERATION PROGRAM I, APPENDIX 89 page (cont'd.) Contents of Table State Brake Propeller 26 Modes Operation Rotor 28 Modes Various for Force Blades 29 3.8 Coordinates Element Blade 30 3.9 Angles Pitch Blade Various for States Element Blade 32 Geometry Windmill Ducted 36 4.1 Disc Actuator 40 4.2 Shown) Are Blades Two (Only Rotor Multi-Bladed a for System Lattice Vortex 41 Rotor Two-Bladed a of System Vortex of Idealization 43 Element Blade Rotor 45 Element Blade Rotor a for Diagram Velocity 45 4.5 4.4 4.3 3.10 3.7 3.6 3.5 Rotor Savonius 3 Effect Magnus 4 Rotor Darrieus 5 1.4 Rotor Ducted Enfield-Andreau 6 1.5 Turbine Wind Smith-Putnam 8 1.6 Machines Power Wind of Performance Typical 10 Device Drag Translating 11 2.2 Airfoil Translating 13 2.3 Ratio Lift-Drag vs Airfoil Translating a From Power 14 2.4 Wind Relative with Airfoil Translating 15 3.1 Turbine Wind a Past Flow One-Dimensional 17 3.2 Geometry Streamtube 21 3.3 Wake Vortex Rankine a with Rotor a for Ratio Speed Tip vs Coefficient Power Maximum Wake Inotational an with Flow for Velocities Induced the on Ratio Speed Tip of Effect 25 24 3.4 2.1 1.3 1.2 1.1 page FIGURES OF LIST Diagram Velocity Blade Gradient Wind a in Rotor 76 Gradient Wind To Due Output Power In Reduction Percent 84 75 6.3 6.2 6.1 Diagram Velocity 55 5.1 Actuator Axis Cross-Wind of Shedding Vortex 62 5.2 Actuator Axis Crosswind Bladed Single of System Vortex 63 Length Equal of Caternary and Circle Troposkien, Turbine Crosswind-Axis a for System Flow 65 70 53 00 5.4 5.3 4.9 = Op Turbine Wind 4.6 Rotor a of State Working 48 4.7 Turbine Wind Smith-Putnam the of Performance Calculated 52 4.8 Smith-Putnam the for Speed Wind Versus Output Power page (cont'd.) Figures of List Disk Actuator Optimum the for Conditions Flow 56 Disk Actuator Optimum the for Parameters Blade Disk Actuator Optimum the for X vs Cp 57 Sums Trigonometric 78 59 6.1 4.3 4.2 4.1 page TABLES OF LIST APPLIED AEROOY:\iAMICS OF WIND lvlAGIINES CHAPTER 1 INTRODUCTI ON Recent interest in wind machines has resulted in the reinvention and analysis of many of the wind power machines developed over the past centuries. Because of the considerable time period since the last large scale interest in this country, which occurred over twenty-five years ago (1) a considerable amount of information that was published is out of print or not generally available. An excellent bibliography of the work published prior to 1945 was collected by the War Production Board in a report issued by sity (2). ~ew York Univer- Golding's work (3) published in 1955 also contains an extensive bibliography and covers the work done in England in the 1950's. It is the purpose of this paper to review the aerodynamics of various types of wind power machines and to indicate advantages and disadvantages of various schemes for obtaining power from the wind. The advent of the digital computer makes the task of preparing general performance plots for wind machines quite easy. Simple, one-dimensional models for various power producing machines are given along with their performance characteristics and presented as a function of their elementary aerodynamic and kinematic characteristics. Propeller type wind turb ine theory is reviewed to level of strip theory including both induced axial and tangential velocities. It is intended that this publication be of use in rapid eval- uation and comparative analys is of the aerodynamic performance of wind power machines. 1.1 Role of Aerodynamics in Wind Power The success of wind power as an alternate energy sources is obviously a direct function of the economics of production of wind power machines. In this regard, the role of improved power output through the development of better aerodynamic performance offers some potential return, however, the focus is on the cost of the entire system of which, the air-to-mechanicalenergy transducer is but one part. The technology and methodology used to develop present day fixed and rotating-wing aircraft appears to be adequate to develop wind power. One of the key areas associated with future development of wind power is rotor dynamics. The interaction of inertial, elastic and aerodynamic forces will have a direct bearing on the manufacture, life and operation of wind power systems while at the same time have a minor effect on the power output. Thus the aerodynamics of performance prediction, quasi-static in nature, is deemed adequately developed while the subject of aeroelasticity remains to be transferred from aircraft applications to wind power applications. 1.2 Wind Power Machines Since 1920 there have been numerous attempts in designing feasible wind- mills for large scale power generation in accordance with modern theories. This section describes representative types of these designs. It is convenient to classify wind-driven machines by the direction of their axis of rotation relative to wind direction as follows: 1. Wind-Axis Machines; machines whose axis of rotation is parall el to the direction of the wind. 2. Cross Wind-Axis Machines; machines whose axis or rotation is perpendicular to the direction of the wind. 2 CROSS-WIND-AXIS MACHINES SAVONIUS ROTOR The Savonius Rotor in its most simplified form appears as a vertical cylinder sliced in half from top to bottom; the two halves being displaced as shown in Figure 1.1. It appears to work on the same principle as a cup ane- mometer with the addition that wind can pass between the bent sheets. In this manner torque is produced by the pressure difference between the concave and convex surfaces of the half facing the wind and also by recirculation effects on the convex surface that comes backwards upwind. The Savonius design was fairly efficient, reaching a maximum of around 31%, but it was very inefficient with respect to the weight per unit power output since its construction results in all the area that is swept out being occupied by metal. A Savonius rotor requires 30 times more surface for the same power as a conventional rotor blade wind-turbine. Therefore it is only useful and economical for small power requirements. Figure 1.1 Savonius Rotor 3 4 full-sized single A design. this with done being little very in resulted locations, top mountain on use for unsuitability its with coupled losses, electrical and losses, mechanical design, aerodynamic poor system's the However axles. car the to connected generators drive and track the around cars the propel would effect Magnus The motor. electric an by driven and diameter, in feet 18 high, feet 90 been have to was cylinder Each move. would flat-cars, on vertically mounted cylinders, rotating which around track circular a construct to proposed Madaras Effect Magnus 1.2 Figure produced. be to cylinder the of axis the and flow the to perpendicular force lift a causing induced is circulation Thus developed. partly only is separation side lower the On eliminated. completely is separation direction, same the in moving are cylinder the and flow the when surface, cylinder the of half upper the On flow. the to angle right a at stream a in placed cylinder rotating a about exists which pattern flow the shows 1.2 Figure cylinder. a of rotating the involves effect Magnus the achieve to way simplest The boundary. solid the and fluid the between velocity relative the of reduction by formation layer boundary suppress to attempts which technique control layer boundary a involves it essence In effect. Magnus the of principle the on works Rotor Madaras The ROTOR MADARAS 5 diameter. in feet 20 than less are built rotors Darrieus largest the date To uncertain. remains more, or kw 100 production, power of levels higher to rOtor type Darrieus the scale to ability The production. power economical for candidate promising a it make production cost low for potential associated and design of simplicity The starting. for input power requires and rotor propeller-type a of that near performance has rotor Darrieus The Ottawa. in Canada of Council Research National the of (20) Rangi & South by investigated been recently has Rotor Darrieus The Rotor Darrieus 1.3 Figure below. 1.3 Figure in sketched rotor axis vertical a for 1926 in patent States United a filed Paris of Darrieus Georges ROTOR DARRIEUS since. done been has development further no but testing for Jersey New Burlington, in built was cylinder 6 they that so designed are blades The mph. 60 to 30 of speeds wind at effective were and pitch blade the vary to used were motors hydraulic speed rotor constant maintain to order In Rotor Ducted Enfield-Andreau 1.4 Figure GENERATOR INTAKES AIR TUR8INE VENT AIR PROPELLER VENT AIR rpm. 95 at wind mph 35 a in kilowatts 100 producing of capable is and diameter in feet 80 was blade The generator. a drives that turbine a through passes it tower the through flows air As tower. high foot 100 the in created semi-vacuum the through air up draws also pedestal blade the and rotor the of tip the between difference pressure the time same the At tips. blade the through tower hollow the from air pulls force centrifugal wind, the by turned are blades the As generator. the and propeller the between coupling no has it machines conventional Unlike 1.4. Figure in shown as blades airplane-type hollow two with windmill experimental an built British the 1954 In ROTOR DUCTED MACHINES WIND-AXIS 7 turbines. wind scale large by generation power electrical of possibilities the illustrated design Smith-Putnam the blade, the of failure structural the of spite In design. this with experimentation ended and off flew blades the of one 1945 In years. two for secured be not could replacement a and failed bearing main inch 24 the when 1943 February until unit test a as operated and 1941 M erected was 1.5, Figure in shown The:turbine, kilowatts. 1,000 generate to intended was turbine wind The edge. leading the on ice of inches six with mph 100 and mph 120 to up wind withstand to designed was plant power The cylinders. oil-filled by damped itself was coning The speed. constant reasonably a maintain still and gusts sudden against guard to 20° to up cone to ability an with designed were blades The edgewise. turning by feather to began blades the increased, velocity wind the As above. and mph 18 of velocities wind at rpm 28.7 of speed constant a at blades the keeping automatic, was control pitch The tower. foot 100 a by supported were and tons 250 about weighed generator and rotor The sections. airfoil 4418 NACA using blades steel stainless two of consisted and feet 175 was diameter rotor The constructed. ever largest the was Vermont in Knob Grandpa's at built windmill Smith-Putnam The DESIGN SMITH-PUTNAM aloft. supported not is equipment generating power the that is system this of advantage main The system. operated power a by controlled and aided is wind the into face to rotor the of motion The gusts. heavy of pressure wind under flap can 8 lift. generate which of all surface, lower the on suction in decrease a and surface upper the on suction in increase an is there and blowing by induced is circulation time same the At drag. viscous in increase accompanying an is there but reduced is drag pressure the Consequently, cylinder. the on back further separation of point the moving thereby cylinder the of surface upper the of layer boundary energy low the re-energizes Blowing separation. flow delay to technique control layer boundary a is briefly, principle, This slots. small from blades the of surfaces upper the around tangentially air of sheets blowing by generated is lift rotor, the of blades cylindrical the rotating of Instead 1920's. the of Rotor Flettner the and Rotor Madams the of that to similar quite is Turbine Wind Rotor Circulation-Controlled the of concept The ROTOR CIRCULATION-CONTROLLED Turbine Wind Smith-Putnam 1.5 Figure 9 constructed. been have that rotors of types various the of comparison performance a gives page following the on 1.6 Figure rotor. circular a of simplicity structural the offset to enough large was area) disk the by. divided area projected (rotor solidity rotor required the ratios speed low-tip at while rotor, the from output power than greater was jet the drive to power compressor the ratios speed high-tip at that found was it and University State Oregon at made was design this of investigation analytical An environment. operating its with cope to structure rigid very a and control, construction, easy for provides design This controls. pitch complicated foregoing thereby slot, the of location the adjusting by achieved is coefficient lift constant spanwise The stiff. very be to it causes blade of type this of cross-section cylindrical a of inertia of moment large The fastened. solidly was that blade propeller conventional a of difficulties the without hub the to rigidly mounted be can blade the because needed is coning or flapping no Second, gusts. sudden with up speed to tend not would rotor the therefore gusts, to insensitive is cylinder the lift zero at First, advantages. of number a possesses design This 10 Machines. Power Wind of Performance Typical 1.6 Figure SPEED SPEED/STREAM 6 5 4 PER 3 =TIP RATIO SPEED 2 Type Arm Four Dutch Rotor Darrieus Rotor Sayonius Type Blade - Multi American Type Blade Two Speed High 0 Windmills Type Propeller for Efficiency Ideal 0.6 (2-1) D Sv C v)2 11 (Ko p (1/2) = Dv = P by expressed is power the that so v - V.Q velocity relative a sees device drag The velocity. translation the and drag the of product the is P, extracted, power the device a such For Device Drag Translating 2.1 Figure device. drag elementary the of action the illustrates 2.1 Figure drag. by driven be to machine the consider First, machine. rotating of element blade instantaneous an as considered be can translation the since machines rotary various examining in illustrative be can devices drag-driven and lift-driven translating of Analysis extraction. power than rather propulsion for used been have devices translating wind-driven Historically, wind. the of action under line straight a in loves that device the is machine power wind of type simple most the Perhaps TRANSLATORS DRAG 2.1 MACHINES POWER WIND TRANSLATING 2 CHAPTER 16 direction. wind in changes to sensitivity and ground the to proximity are translators of disadvantages Other land. and machines in investment capital extensive mean speeds large as disadvantage chief the are rates extraction power high achieve to translator the for required speeds large The speeds. low at velocity translator of independent relatively is translator a by produced force the contrast In velocity. translation the with linearly vary to seen is translator a of output power the velocity, wind the below speeds At wind. 17 Turbine Wind a Past Flow One-Dimensional 3.1 Figure motion. rotational no with axial entirely be to assumed is flow the if power and thrust the determine may we flow the to energy and momentum, continuity, Applying device. wind a by slowed is which V. is wind stream free The below. shown as turbine wind a past flow consider (5,6) Froude E. R. and W. and (4) Rankine by originated theory momentum axial the with Starting THEORY RANKINE-FROUDE 3.1 output. power to geometry blade linking approach detailed more a. to proceed then and turbine wind a of output the of analysis one-dimensional a consider will we step first a As production. power wind scale large for candidate leading the and machine efficient most the (1), 1940 in as today, remains turbine wind or windmill type propeller The turbines. wind to attention our turn us let Now THEORY MOMENTUM GENERAL ROTORS; AXIS WIND 3 CHAPTER +umv. 18 Or 2 c° (v. upA 2 }= 2 pAu = P 1y,20 p. = pi with flow, isothermal assuming thermodynamics, of law first the From is. power the however, importance; great of immediately not is thrust The disc. the at change velocity the twice is ui, - V. change velocity wake final the , 2aV. Ui= - V. that note aV., u- denote we If velocities. final and initial the of average the is disc the at velocity the i.e., 2 (3-4) =U ui + obtain we expression momentum the with together 2 (3-3) p T (V02,, that so wake the and turbine the of side downwind the between again and turbine the of side upwind the and stream free between used be may Equation Bernoulli the Now -p- =p Ap (3-2) , where AAp = T machine wind the by caused drop pressure the of consideration from Second -ui) (Voo pAu )= (3-1) =T (Vo(, theorem momentum the from First, obtained. be may thrust the for expressions Two 19 energy, kinetic translational to addition in wake the in energy kinetic rotational is there If sense. opposite the in rotates wake the (windmill), device extracting energy an of case the in propeller, the of direction the in rotates wake the propeller, a of case the In rotate. to wake the cause will machine wind rotating a with interaction rotational, not is stream initial the As rotation. wake of consideration additional the with accomplished be can modeling one-dimensional Further 88.8%. is coefficient power maximum at efficiency The 0.5. of coefficient power a yields which 1/2 = a at 100% is efficiency maximum The 2 (3-7) a) 441 pAu = V2 by given is available power by divided output power efficiency, the Hence Au. but AV., not is disc the through rate flow mass the since efficiency maximum the represent not does however, (3-6), Equation rotor. the by out swept that to equivalent area an in contained wind the of energy kinetic the is denominator the that noted be may it (3-6) equation examining When . 1/2 = axam obtain we 2a), - (1 V., = ui as so zero, is velocity wake final minimum The air. the on turbine the of influence the of measure a is and factor interference axial the as known is (a) term The defined. is power maximum a Thus (3-6) Pmax 16 pAV.3 1/2 27 1/3 = a when maximum a has which (3-5) ) 441 = pAV:: 1/2 20 bounds. establishing in results the to utility affords which model simple a yielding inserted core rotational a and out subtracted be may velocities angular high of regions the of contribution the however axis, rotation the near velocities rotational unrealistic produces irrotational, be to assumed if model, flow wake The estimated. be may removal power on rotation wake of effect the turbines, wind of analysis the to notation his Adopting propellers. of analysis the in rotation wake of effect the considered (7) Joukowski ROTATION WAKE OF EFFECT 3.2 torque. low and velocity angular , high means which low is ER2 when occur will extraction power greatest the ETi energy initial of amount given a for so, energy, kinetic rotational wake greater thereby and momentum angular wake greater produces torque increased that note velocity), (angular x (torque) = P as ER2 T2 E ET1 =P thermodynamics From Translation Rotation ER2 + T2 Extracted Power P= Energy Kinetic Final E = ETi = Energy Kinetic Initial velocity. angular rotor to energy kinetic rotational wake relate will example simple following The translation. only having wake the of case the in than extraction power lower expect may we considerations thermodynamic from then (3-9) 21 ri2(01 = r2CO Momentum of Moment (3-8) uiridr = urdr Continuity are: equations resulting The geometry Streamtube 3.2 Figure Wake Rotor streamtube. the illustrates below 3.2 Figure wake. the in and rotor the at velocities induced the of values relative the on rotation of effects the of measure a is approach this of outcome main The obtained. be can coefficient power the for expression an cases, special certain for addition, In rotor. the at velocities corresponding the and rotational, and axial both velocities, wake the between relation the express that written be can equations analysis, streamtube a Using 22 obtained. be also may element annular an for thrust and torque the for Expressions zero. be to assumed been has drag Fluid rotor. the at discontinuously changes rotor the of rotation of direction the opposite is which fluid, the of velocity angular The radially. vary velocities axial wake and rotor The velocity. rotational the to due wake the across varies pressure The noted. be may flow the of features Several equation. Euler's and equation Bernoulli's are used equation momentum the of fauns particular The solution. a obtain to order in co, say variables, the of one of specification needs one and obtained be cannot Closure wake. the in flow and torque thrust, between relations the obtain to used be may equations four These 1) 1 (3- 2 \ dr]. ) (a)? d wi) (c2 2 2 \ dr1 ( d obtained. be may velocity axial in gradient radial the for expression an Finally rotor. the of velocity angular the is 5-2 where U (3-10) ulahri2 2 U1 2 + (01 (0" = + 00 2 / (u1 )2 Energy equation, energy an obtain may we addition, In fluid. the of velocities angular wake and rotor the are coi and co where (1 a)2 b a b2 23 A 0/003 y2 power cp and a), (3-12) (13 4X2 42 (1 1 2 b' =a obtain may We a) (1 Voo a u b) (1 V., Defining constant. is velocity axial wake the constant is r2o) when that seen be may it gradient, velocity radial wake the for expression the From r2codA + p(S) 22-2) = dT THRUST pur2o3dA = dQ TORQUE (3-13) N)b] (1 + 24 a a)2[2Na b = Cp 11(1 obtain we N::----0/coma, Letting wake. vortex Rankine a substitute may we wake, vortex irrotational an of lieu In axis. the near velocities infinite produces constant = r2e) since modification some requires coefficient power The 2. above ratios speed tip for wake in value the 1/2 approximately always is disc the at change velocity axial the that observed be may It X. and a of function a as a/b ratio the of variation the illustrates above 3.3 Figure Wake. Irrotational an with Flow for Velocities Induced the on Ratio Speed Tip of Effect 3.3 Figure -u 0.5 0.4 a: 0.2 0.3 0 0.1 0.2 0.4 III 8 0.6 0.8 I.0 25 the continue to simple quite is it 0 < a For 1. < <a 0 is that device, extraction power draglike a as operating is device the that assumed tacitly been has it analysis previous the In STATES FLOW MULTIPLE OF MODEL SIMPLE 3.3 turbines. wind of theories element blade in rotation wake neglecting of effect the into insight some affords it model, this with associated difficulties the of spite In model. flow this criticized recently has (8) Goorjian tubes. steam interacting non- annular, in occur to flow the requires results these at arrive to used model flow The Wake. Vortex Rankine a with Rotor a for Ratio Speed Tip vs Coefficient Power Maximum 3.4 Figure RD. 5 4 2 3 0 I 0 DISTRIBUTION VELOCITY ROTATIONAL WAKE 0.2 0.3 8 n> 0.4 0.5 0.6 WMAX least. the are rotation wake the consequently and torque the where ratios speed tip high at occur coefficient power of values highest the expected be would As 3.4. Figure in below shown is wake vortex Rankine a with rotor a for coefficient power maximum The (3-16) 26 11al 4a = CT form the in written be can cases three all Thus, (3-15) a) (1 4a (3-14) pAV:, X = , = CT Force (1. 4a = Cp that case this in find we 3.1 Section in as approach same the using analysis the Continuing State Brake Propeller 3.5 Figure below, shown is pattern streamline idealized An state. brake or thrust, reverse the in propeller a is that flow, forward a induces it that so adjusted pitch its with propeller powered a considering by modeled physically be may This 1. a> for occurs case interesting particularly A propeller. a of type that of typical is regime flow This flow. wake the to energy adding and thrust producing propulsion a as act will device the that show to analysis .5 1 1 28 Modes Operation Rotor 3.6 Figure a i i 0.5 1.0 0 -0.5 1 Flow To Added Power _ 0.6 0 op 0.6 F/ow From n Extracted Power f I I 0.5 1.0 1.5 I I I I a 0 1 -0.5 _ -1.0 1 THRUST .---v-A" Propeller Windmill 0 Theory Momentum Brake ---4.-- _ Propeller // (emperical) Glauert A _ 1.0 // 1 t DRAG I 2.0 I 29 Modes Various For Force Blades 3.7 Figure Direction Wind a>I Brake Propellor 0<a<I/2 Windmill 0=a Slip Zero a<0 Propellor Vco r.r1 a 9 aVo S7:7=1V., ./1 Force Blade v/ rf2 Rotation of Plane 30 Coordinates Element Blade 3.8 Figure a)V. (1 Rotation of Direction L' Direction Wind 3.8. Figure in sketched is model This itself. disk the at that twice is flow induced wake the assuming and terms swirl ignoring theory element blade conventional use and (propeller) rotor axis wind the example, an as consider, will we model simple our For themselves. elements blade the on forces lifting by represented as that to momentum wake by represented as force the connect must we modes the of possibility the establish to order In wake. the in flow the considering by and itself disc the at flow the considering by both states these of models physical construct can we Thus, here. down break will model simplified our since 1 = a of vicinity close the in regimes flow the avoided-discussing have We blade. the on torque and force the of sense the illustrate also which 3-7, Figure in sketched are states These 1. a> state, brake propeller the enters rotor the negative, increasingly becomes now 0 As rotation. of plane the to relative angle zero at be to blade the for is, that 0; = 0 for exist still can state windmill the that noted be should It 1/3. = a at occurring (3-23) 31 ila 4a 01= sin x a)cos K1 47cxa a all for write can we Thus cdrircrdr. = a as a solidity local a define can We previously. as result same the by given is force blade the , while a), - -4a(1 = CT theory momentum by get we 1 a> state propeller-brake the For rON.. ratio speed tip local the is x where (3-22) 0] xsin 0 a)cos ( XC = CT OrFdr = dT (3-21) by given is annulus the on force the Thus (3-20) 0] sin Or 0 a)cos (1 pnc[Vca = a, 27csin = CL with and WcCL/2 = F from circulation the get we itself element blade the at flow considering Now a) 441 (3-19) = CT by given is coefficient thrust local the and Ircrdr a)2a (3-18) (1 pV02 = dT by given is annulus the on force the theory, momentum By 1. < a state windmill or propeller the in are we Assuming 32 than larger much becomes constant) = 8 (following disk the on drag-force the now increased, slightly is flow induced the a, B, at that Assume follows. as is unstable is B state why of explanation simplified A approached. is state the how upon depending occur and stable both are C and A that and unstable is B as shown point the that appears it case, mode triple the For ratio. speed tip and solidity of fiuiction a is lines force blade the. of slope the that note to interest of is It Angles Pitch Blade Various For States Element Blade 3.9 Figure 1.5 1.0 0.5 a -0.5 AMMO Brake Propeller mode. brake propeller one and modes windmill two states, equilibrium possible three exhibit 0 > 0 02> range intermediate the in angles The occurs. mode brake propeller the <82 0 for while occurs, propeller thrusting powered simple the <81 0 for that Note 3.9. Figure from seen be easily most can equation this to solutions of nature The 33 (16)]. [Shapiro, occur states ring vortex the and wake, turbulent the brake, parachute the of states anomalous the where rotor descending lifting a with associated that is region this analysis helicopter In theory. rotor helicopter with connection in problem this on done been has research extensive quite although region, this in flow for exist theories satisfactory No 1. = a of vicinity the in inadequate quite considered be must analysis brake propeller simple the Again unacceptable. physically is which configuration streamline a infinity, downstream and disc actuator the between somewhere velocity wake zero and wake far- the in reversal flow implies here developed model dimensional one- simple the 1 < <a 0.5 for example, For 0.5. a> for valid considered be not should thus model, perturbation small a considered be should analysis present the that here note We characteristic. the of region X low the at occurs which stall, blade as same the not is behavior this that Note reduced. is a which in technique feather blade normal the from distinct quite is which control speed of method a is This energy. dump to state brake propeller the of flow confused the use to possible be may it loads, torque shaft reduced or winds incoming high to due speed over rotor prevent to necessary is it where cases in However, windmill a of range design major the in occur not should 0.5 a> of states that note We continuity. flow violate somehow will 0.5 < a of value the with annuli outer and inner has which annulus an on 1 < a giving model a that seen be can it example, For inconsistencies. flow involves inevitably it that and model idealized an is above the that stressed be should It occur. can 1 < <a 1/2 with solutions no that is theory element blade in assumption working a Thus arguments. these to according stable are C and A hand, other the On 1.0. = a towards moves system the and reduced, further is momentum wake this thus momentum, wake the by represented that 34 pressure; static freestream at exit duct the leaves flow the that assume to usual is it performance propeller ducted of calculations In technically. effective not is propeller shrouded the account, into taken are moments pitching duct other and drag duct when and increased, is speed forward the as reduces shroud the of effectiveness the friction, skin ignoring even that, shown be can It speed. forward zero at least at ratio, thrust/power its increase thus can and propeller thrusting a of contraction slipstream the reduce effectively quite can duct a that established well been has It propellers. powered of thrust static the increase to used frequently are ducts or Shrouds ACTUATORS DUCTED 3.4 disc. the for a mean the is given perturbation axial of value the and a, uniform non- to subjected is rotor the fact in thus remainder, the driving is rotor the of portion one state autorotative the in that noted be should It state. autorotative the terminology, helicopter in or 0, = Cp to correspond tests these running, free were these Since 3.9. and 3.6 Figures in shown was curve This tests. windmill free-running of series a from data using and concepts these using (10) Glauert by constructed was a versus CT of curve performance generalized A (18). Townend and Bateman, Lock, by given is problem this to approach classical A flow. axial for occur which singularities the of some eliminates freedom of degree additional this of introduction The axis. rotor the to angle small some at yawed but axial, precisely not is flow freestream the that assuming by removed be can 1.0 = a near flow of anomalies the of many that Wolkovitch, by described as note, to interest of is It (17). Wolkovitch by discussed is a of range entire the for performance Rotor occur. well may 0.5 a> with solutions spurious conditions off-design for However, 0.5. a> for conditions analyze to necessary seldom is it thus 0.5; than less is a modes operating windmill normal most For 35 as extracted power the write immediately can we , rh is system the through flow mass the Assuming system. windmill ducted typical a show we 3.10 Figure In justify. to hard quite are which assumptions without device this on made be cannot analysis type momentum a rotor, free the unlike that shown is it which in follows, this of analysis simple A capacity. extraction power its increased and rotor the through drawn be to flow more caused has duct the effect In 0.593. of limit rotor free the exceed will coefficient power the area, rotor on based then, velocity, stream free the thirds two of level optimal the at flow induced axial wake the keeping still white this, than larger be to section cross wake optimal the cause to possible is it if Thus, disc. windmill the of that twice be should section cross wake optimal the windmill free a for that showed have We expansion. wake the increase to be will duct a of effect the viewpoint, physical a From (19). Rainbird and Lilley 'y given is windmills ducted of analysis comprehensive A performance. superior have might windmill ducted a that suggested been frequently has it duct, a to due performance propeller thrusting in improvement the of Because there. pressures low the to due duct the of area entry and edge leading the on force the is contribution this of part major a and duct, the on thrust forward a by represented is force increased the that noted be should It contraction. slipstream no been lave will there thrust, the increase will propeller the as section cross same the of duct cylindrical a even that observe to interest of is It system. the of ratio thrust/power the increase will this than less be to contraction slipstream final the causes which duct any Thus area. propeller the half one is slipstream ultimate the propeller, free static a of case the In section. cross wake ultimate the as taken be may area exit duct the calculation, of purposes for and velocity slipstream in change further no is there consequently, 36 required. is assumption additional one theory momentum using Thus, edge. leading the to close very region the for except calculated, be can interior duct the on pressure the theory one-dimensional By known. not is duct the of outside the on field pressure the since theory momentum simple by determined be cannot force duct the but AAp, by given is force propeller the that true still is it duct, the with case, our For case. propeller free the for a) - pAVoo(1 = th result the gives immediately This area. actuator the is A where AAH = AAp = T by given is which actuator the on force the is system the on force the that stating by obtained readily is equation remaining the theory actuator free For th. for expression an have not do we that in closed not are equations these that note We (3-25) 2a riiVao = T as written be may duct) and (rotor system entire the on force This (3-24) a) (1 2a MY! = MAR = P Geometry Windmill Ducted 3.10 Figure vs. 37 higher and flow mass higher a with duct the of downstream expansion wake gives case, the be must which static, freestream than lower is pressure exit the assuming that, seen be will It (3-29) b) (3-28) 2a b) b)(2 (2a 41 (1 4a = = C; Cp us give which C*p coefficient pressure exit duct the and area) exit on (based coefficient power the writing by expressed be can This duct. the for condition flow exit of assumption the by determined are characteristics performance all analysis of level this At alone. rotor the of that exceed will area, rotor on based system, ducted the of coefficient power the then 1.54 exceed ratio area rotor to duct the if that observe and (3-27) /A 2a)Ae 41 (1 4a = Cp get we then area, rotor of terms in coefficient power write we If 0.211. = a at 0.385 = (3-26) 2a) Cp.. 41 give to maximumized be can expression This 4a = Cp obtain we A, area exit duct the on coefficient power the basing Then, a). 2 - AepV.,(1 Iii= as determined be can flow mass the and 2a = b get we then static, freestream is exit duct the at pressure the that theory, propeller ducted powered in done is as assume, we If b). - V.,,(1 as shown is which exit, duct the at velocity the assuming by satisfied be to this consider can We 38 loadings. rotor different at system given a for even and system, rotor duct every for notably vary will which quantity this on dependent directly is result the since approximation; poor a is coefficient pressure exit the assuming- that appears It flow. entire the of modeling a upon depends prediction performance proper a and method simple any by analyzed be cannot windmills ducted Thus wake. the surrounding tube vortex associated the with energy, different of wake a implies disc actuator the of addition essential the since flow homoenergetic uniform a in wing ring a as simply treated be cannot duct the that note We analysis. this into enter must geometry pressure ensuring and duct the of details the Evidently surface. bounding wake the on continuity flows, external and internal computing contour, a assuming techniques, flow potential by shape wake the compute to principle in possible is it sections, previous the in described As pressure. exit duct assumed the of terms in plotted power is performance the noted be must it paper Rainbird's and Lilley studying In coefficient. 39 the that Assume process. shedding ring vortex the of model a create can we porosity, infinite to zero from switched be arbitrarily may .which disc a actuator, prototype the consider we If flow. freestream the to parallel is tube vortex wake the that assumed is it where disc, actuator the for used are assumptions Analogous deformation. wake for account to necessary is it that wings loaded highly very of cases in only is it However, situation. inconsistent kinematically a wake, the through flow downwash be will there that implies This flow. freestream the to parallel wing the leaves wake vortex the assuming by removed usually is problem the of nature interactive the however, theory; wing ordinary in occurs situation similar A consistent. are fields pressure and streamline wake the assure to checked flow induced the and assumed is strength and geometry initial the where process, iterative an by determined be generally must strength and shape wake the words other In flow. the of dynamics the and kinematics the both involve must wake inviscid the of solution proper a Thus equilibrium. in is it whether determine to wake the on fields flow and pressure the compute to possible then is It wake. this of flow induced the calculate to Law Biot-Savart the use then and distribution vorticity wake the stipulate usually we models wake advanced more In flow. the of models developing in assistance great of be can geometry, its and vorticity, this of generation of mode The vorticity. of sheet a by represented be may head in discontinuity the flow, inviscid an For mainstream. the from head total different of flow a of consists system windmill a of wake The WAKE THE OF REPRESENTATION VORTEX 4.1 THEORY VORTEX/STRIP ROTORS: AXIS WIND 4 CHAPTER 40 low. fact in is torque the power given a for that so large be must ratio speed tip the windmill, type propeller a of model approximate an be to this For torque. no is there hence and wake the in velocity tangential no has system this that observed be will It disc. the at that twice is wake downstream the in flow induced the that analysis, momentum the from obtained already result the demonstrating of way another is This tube. semi-infinite a of end the at that twice becomes flow axial the and removed are flows radial singular the then system, this to added were strength appropriate of tube vortex another f I edge. tube the at infinite are flows radial the although section, cross the over flow axial induced uniform a gives solution the state to except here, these into go not will We end. its at tube vortex semi-infinite a of flow induced the compute to available are methods Standard disc. actuator the as diameter same the have will tube vortex the loads, light of hypothesis an using and developed, is strength constant of tube vortex a assume we if limit, the In Disc Actuator 4.1 Figure 4.1. Figure in shown as freestream the with downstream convected be will which vortices ring of series a shed now will disc The motion. rearward the during porous fully and mainstream) the (against motion forward the during solid is and backwards and forwards oscillated is disc 41 inside located be could induction different completely of annulus Another systems. tube vortex circular two superimposing by seen be can as annuli, other affect not does system a such of flow induced the words, other In cylinder. annular this to confined entirely perturbations tangential and axial with model self-consistent fully a is this mainstream, the to parallel cylinders circular right considered be may boundaries wake the which in system loaded lightly a For Shown) Are Blades Two (Only Rotor Multi-Bladed a for System Lattice Vortex 4.2 Figure itself. disc the at vorticity radial by connected geometry, similar of lines vortex spanwise and ring of consists tube vortex inner the of surface the Then annulus. an is disc actuator the that assume to is model this of variant A 4.2). (Figure cylinder wake the along vorticity streamwise distributed with strength finite of vortex central a implies this that see we lines, vortex of kinematics the on Laws Helmholtz's satisfy to order In circulation. blade constant of system many-bladed a representing disc, the of plane the in lines vorticity radial of number large a with this model can we theory, disc actuator with Consistent torque. introduces which one is model simple this to add to refinement next The 42 realistic. more becomes sheet vortex bounding continuous a of idealization the that so packed, densely more be to tern sys helix finite the cause will blades of number large a or ratio, tip-speed large a that also note We 4.3. Figure of system helix the of components as considered be could. systems vortex streamwise and ring the where 4.2, Figure of wake the of that to structure similar somewhat contains model bladed finite this that note We ratio. tip-speed the to related directly is vortices the of angle helix The 4.3. Figure in sketched as becomes geometry vortex wake the then flow, local the to parallel lies vortex the that and tips and root the at only occurs shedding vortex that Assuming occurs. situation different somewhat a velocity finite a at rotating and blades of number finite a having system rotor realistic more a consider now we If models. simple in assumed as head, total reduced of be to flow wake the permits it Thus sheet. the by separated flows the between head total in differences permits rings vortex of composed sheet vortex bounding continuous a of concept the that also note We large. be should ratio speed tip the and blades of number the of product the that requires valid be to theory element blade interactive non- for Thus annulus. an of induction the isolates effectively which tube wake vortex the on vorticity streamwise continuous of idealization the is it that apparent is It stations. other all at flows induced affect will- station spanwise one at geometry in changes where theory, wing in situation the from different is this that note We interact. not do annuli that assumes which theory element blade of basis the is independence annular of result interesting This flows. induced adjacent affecting without changed be can annuli neighboring in blade the of chord or attack of angle the and annulus that in geometry blade the of only function a is annulus each of system flow induced the Thus, first. the in flows induced the affecting without one this outside or 43 here. it discuss not will we and most than complicated more is model elegant This Model. Goldstein the termed generally is sheets vortex helical of system a sheds blades the which in model The wing. ratio high-aspect rolling a as modeled is rotor the where (21), Kuchemann by given is ratio advance low very at system rotor two-bladed a for analysis An ratios. advance low at blades few with rotor a for approximation an considered be must theory element blade that so sections neighboring influence does section spanwise each on load the that sense the in interaction spanwise is there model bladed finite the for that noted be will It blade. the from distance short a adequate quite be may vortex tip strength finite a of idealization the that so tip the near concentrated is voracity this Generally, edge. trailing the from shed is voracity of sheet continuous a and wing yawing a of that to similar quite becomes situation local the Thus there. washes induced infinite imply would this since tips, the from shed be cannot strength finite of vortex a Consequently, wing. ratio aspect high a of that to similar is system vortex and flow the blade each near that illustrate will 4.3 Figure of examination However, Rotor Two-Bladed a of System Vortex of Idealization 4.3 Figure (4-4) 44 a. attack of angle local the and W velocity relative local the upon based coefficients drag and lift sectional the- are (I) COS CD and CL where CD sin(I) CL = Cx ID a' + 1 = (4-2) sing) CD ± 4) cos CL (4-3) Vco a (4-1) (13, Cy tan 1 (I) = a verified be may relations trigonometric following the diagram, the From direction. downwind the in blade the to normal is y-direction the and x-direction the in is rotation of plane The a. attack, of angle local the and 0 angle pitch blade local the to relation in shown is W, wind, relative the Here 4.5. Figure in rotation of axis the towards looking tip the from viewed is 4.4 Figure in illustrated rotor turbine wind a of element The follows. as proceeds station, radial each at flow 2-D locally assume to seen be can which method, The theory. strip and theory vortex theory, element blade theory, element blade modified including names of variety a by called been has velocities induced the with conjunction in used when method This tubes. stream circular non-interacting in occurs rotor the through flow the that assume to is rotors helicopter and propellers for calculations performance for method accurate and used frequently A EQUATIONS FLOW ANNULUS 4.2 45 Element Blade Rotor a for Diagram Velocity 4.5 Figure Element Blade Rotor 4.4 Figure vc. (4-9) Cdr 2 46 w2 pBc = dQ is torque blade-produced The disk. rotor the at velocity angular the twice be to assumed been has stream slip the to imparted velocity angular the where (4-8) (2an) (27Erdr)ur p = dQ obtains one theorem momentum of moment the From tube. stream differential annular an in element blade the from developed torque the to equated is considerations momentum angular from determined torque the manner, similar a In 11) sin2 87cr (4-7) 1-a a BcCY obtains one 2a, = b factor interference axial wake local the that assuming and expressions two these Equating (4-6) Bc = dTB pW2Cydr c, chord local having each blades B for while 1 (4-5) ) u (Ka u (27crdr) p dTm momentum From considerations. aerodynamic element blade from predicted force axial the to considerations momentum by dr thickness of element annular an in generated dT force axial the equating by obtained be may blade the on developed forces the and a factor interference axial the between relation A 47 A valid. not is analysis above the therefore, (4-10), and (4-7) equations to leading assumptions the with consistent not is pattern flow a Such occur. may flow recirculating that seen be may It 4-6. Figure in below illustrated patterns flow the note procedure, above the qualify to First, qualification. and modifications some required far so developed expressions The readily. quite accommodated be may taper blade and twist changes, section airfoil Blade rotor. the of force axial and torque overall the determine to integrated be may force axial and torque to contributions local the and known are properties flow sectional the converges iteration above the Once repeat and B step to back Go Cy and Cx 4-4) and (4-3 Calculate a (4-7) Calculate a' (4-10) CD and CL Calculate Calculate Calculate (4-1) (4-2) (i) Calculate start) to acceptable is 0 = a' = (a a' and a Guess S2 V, 0, CD(cc), CL(a),. c, r, Given procedure: following the by determined be may r station radial given a at conditions flow local the then available, is data performance sectional airfoil suitable If .2(1) sin 47cr BcCx (4-10) a' 1+ a' relations these Combining 48 ring vortex (e) windmill; turbulent (d) windmill; (c) zero-thrust; (b) propeller; (a) Rotor: a of States Working 4.6 Figure (e) ---s"--"----_,__------- )d( Cc) (b) c) ( rotor. a of states ring vortex and windmill turbulent the quantify to results experimental used (10) Glauert 4-6. Figure in illustrated states various the through pass can descent autorotational to ascent vertical from going in helicopter, A section. next the in modified be will consideration This occur. can recirculation , 'A a> for hence 2a), - V00(1 = u1 wake the in velocity The considerations. momentum wake from obtained be may flow recirculating of onset the determining for criterion 49 follows. as proceeds velocities induced for equation into factor loss tip the of incorporation The used. be can solution simple a yields which model Prandtl the blades, more or three involving situations for results in difference little is there Since use. to difficult more is it functions, Bessel modified of series infinite an involves model flow Goldstein's since however, accurate more the is model Goldstein the models two the Of position. radial and blades of number ratio, speed tip of function a is F factor The blades. of number infinite an with rotor a for circulation corresponding the is Fc, and r station radial a at circulation the is F blades, of number the is B where (4-11) that such F, factor circulation-reduction is approach Goldstein's and Prandtl's of result The tips. the at interaction wake to due circulation of reduction the for models developed and contraction) wake (negligible propellers lightly-loaded about flow analyzed have (12) Goldstein and (11) Prandtl radius. actual the of 97% of order the on characteristically radius, actual the of fraction some to radius rotor maximum the reduce to being these of simplest the approaches, of variety a in treated been have losses tip So-called neglected. be cannot effects wake the however, machines; power wind most for neglected be can acceleration radial of effects The pattern. flow assumed the alter can tip the at flow wake-induced and acceleration Radial dimensional. two be to assumed been has position radial any at flow The vorticity. shed of pattern the of because modification some requires analysis previous The MODELS LOSS TIP 4.3 50 > aF becomes flow recirculating for criteria the that noted be may It convergence. for required iterations of number the in reduction significant and performance higher slightly yields (4-12) of lieu in (4-14) equation of use The II. Appendix in given is (4-14) and (4-13) equations of derivation The (I) (4-14) S1I12 8 = aCY aF)aF (1 quadratic a becomes (4-12) equation however, same, the remains (4-13) Equation aF). - V.(1 = u by given then is rotor the through velocity flow average The velocity. wake the as manner same the in vary to assumed is (4-5) equation in disk rotor the through u velocity flow axial the in made be can analysis the of refinement further A a is . 7tr a by given solidity local a quantity the and factor correction tip Prandtl the or correction tip Goldstein the is F where (I) (4-13) cos 4) sin 8F aCx (I) (4-12) 1+a' a' a aC - sin2 8F a 1 become then (4-10) and (4-7) Equations 2a'FQ. written is change velocity angular the manner, similar in and 2aFV. becomes 2aV. change velocity the Thus velocity. this of F fraction a only is change velocity average the and sheets vortex the on only occurs slipstream the in 2aV., or ul) - (V. velocity, axial of change maximum the that virtually is correction tip the of meaning physical The 51 speed tip low At machines. wind concerning generalizations some illustrate to used be can also 4-7 Figure ratios. speed tip low at available power the increase can but power maximum the reduces pitch Increased 4-7. Figure in seen be can angle pitch of effect The curve. the develop to used was correction tip Goldstein The chord. 11'4" an with feet 175 was diameter turbine The length. foot 65 a along 50 twisted discontinuously has which airfoil 4418 NACA an employed turbine Smith-Putnam The ratio. speed tip of function a as (1) Turbine Wind Smith-Putnam the of coefficient power calculated the gives 4-7 Figure noted. be should analysis previous the of nature approximate the blade, the along circulation of distribution optimum with rotor frictionless a for derived been has F factor the As 4) (4-16) sin R 2 Rr =B f where 7C (4-15) Lexp r -1 A cos 2 =F by given is factor F Prandtl's calculations. the in factor dominant a being instead correction, loss tip a be to ceases approach this cases such In blade. entire the over appreciable is loss tip the ratios speed tip low at that noted be may it consideration practical a As determined. be can F(p,,g,,a) = F factor correction tip Goldstein the thus and RpIr = The cot.* IA tiao is ratio speed tip corresponding relation the via ratio speed local a defines 4) angle The /R). r (q), F = F that so (I), of value local the on F of calculation the bases approach Lock's (13). Lock of method the following determined be may rotor loaded heavily a for correction tip Goldstein The 12 52 (4-13) and (4-12) equations 00, = °pitch (4-13) and (4-12) equations 5°, = Opitch (4-14) and (4-13) equations 00, = °pitch Turbine. Wind Smith-Putnam the of Performance Calculated 4.7 Figure R l0 4 8 0.1 0.2 cq o 0_ itl>8 0.3 0.4 0.5 stability. the greater the curve, the steeper The speed. original its to rotor the return will turn in which output power positive in result will speed rotational decreased velocity, wind constant for since stable, be will (feathered) output power zero at operation rotor the negative, is 0 = Cp at curve power the of slope the If zero. become will output power net the ratio speed tip large some at Finally velocity. angular increasing with power in decrease rapid a in result will coefficient drag high A dominant. becomes drag of effect the coefficient, power peak the above ratios speed tip At speed. design the below operating when stalled be can stations, inboard the partieularly rotor, the of much and ratios speed tip low at large is (1) angle The coefficient. lift maximum the by influenced strongly is coefficient power the ratios, 53 -= Op Turbine Wind Smith-Putnam the For Speed Wind Versus Output Power 4.8 Figure Rn V. 0.5 0,4 0.2 0.3 0.1 0a. 1.1J cc 0 N) a. In 0 111 10 12 4-7. Figure in shown calculations turbine wind Smith-Putnam the illustrates 4.8 Figure I/X. by given is velocity while Cp/X3 to proportional directly is power the variables, our as X and Cp Retaining velocity. wind versus power of plot a is performance rotor illustrates that display of type Another velocity. wind given a for speed rotation and efficiency, output, power concerning infollnation yields ratio speed tip versus coefficient power of plot A 8) 1 (4- 54 a(1a) = a'(1a')x2 equation energy the is This required. is relation another variables, dependent two involves power the for integral the Since Vco u o, V =a , Voo = = a' and RS) Vco rQ =x where (4-17) x2 = ° dx 3 ix pVco37CR2 Y2 8 = CP is coefficient power the for relation The ratio. speed tip given a for output power maximum the yielding results the constraint; energy an to subject stationary made is integral power The power. the for integral an up set and blades) of number infinite an with rotor a to corresponds (i.e., disk actuator rotating a as rotor the treat to is used approach The windmill. optimum the for model simple a developed has Glauert GLAUERT ROTOR; OPTIMUM THE 4.4 fluctuations. speed wind to sensitivity greatest the hence and velocity wind in increase given a for power in increase greatest the give will coefficient power maximum of point the near Operation coefficient. power maximum of location the is importance considerable of point Another velocity. starting the controls drag and output power maximum the controls stall the angle, pitch and RPM constant at that Note (4-18) 55 a) (1 a = a')x2 a'(1+ that So (4-19) a'rf) a')rS2 (1+ = tan 4\7,0 (1 are These velocity. relative the to normal is velocity induced total the that condition the under developed be may tan for expressions Two velocity. relative the to perpendicular hence and lift to due be must rotor the at induced velocity the drag, of absence .the In Diagram Velocity 4.9 Figure Rotation of Plane Direction Wind assumed. be may flow two-dimensional conditions, these Under variations. circumferential no with streamtubes annular in uniform be to assumed is flow The plane. rotor the at velocities the consider to is relation this illustrating of way unique most the Perhaps 56 afx2 x 0 0 .0584 0.157 .1136 0.374 .1656 0.753 0.031 .2144 2.630 0 .2222 00 0.292 0.812 2.375 00 a' 1/3 .33 .31 .29 .27 .25 a Disk Actuator Optimum The For Conditions Flow 4.1 Table rotor ideal an of most that seen be can it more, or 7 of ratios speed tip reach easily rotors speed high Since 4.1. Table in given are x and atx2, a', a, in variation The 1/4. 1 4a = a, (4-21) 1) a)(4a (1 = atx2 (4-22) . ._ a . ._ 1/3 Hence, that so 3a yields solution The a) - a(1 = = at)x2 + a'(1 0 x) a', G(a, With " P JO = C x)dx a' Fla rX (4-20) posed now is problem variational The 57 lift. is blade the on acts that force only the zero, is drag the that assumed have we since course, Of configuration. blade the to relation in forces and velocities the illustrate to used be may 4.5 Figure determined. be may (I) angle the and velocity relative the position, radial each for known are a' and a quantities the As theory. element blade the using model this from obtained be may infoimation Further 0.5 .288 1.0 .416 1.5 .480 2.0 .512 2.5 .532 5.0 .570 7.5 .582 10.0 .593 voo Cp RS-2 Disk Actuator Optimum The For X vs Cp 4.2 Table 1.6. Figure in illustrated is ratio speed tip with Cp of variation The zero. approaches rotation wake the and 0.593 approaches coefficient power the ratios, speed tip large At wake. the in energy kinetic rotational large the of because low is coefficient power the ratios speed tip low At 4.2. Table in given is ratios speed tip various for coefficient power The 2V t rV 2V 02 (2/9) --> cor2 a'x2 Go, --> x as i.e. vortex irrotational an of form the in distributed velocity rotational the and 1/3 = a with operate will CL .7. 58 xa-.= at maximum a approaches that chord a have will constant and X given a for blade optimum an that noted be may It results. the gives 4.3 Table determined. be may blades the of shape the that so x of function a as known are a' and a Now (4-28) 4)cos4) sin 8nr sin BcCL (I) (4-27) (I) sin2 87cr cos BcCL a' 1+ a' a - 1 a' if, that So (4-26) (4-25) = a)a'dr (a 47cr3pVc00 dQ a)adr (1 4npA72 = dT 2a) = b (assuming yield expressions momentum The (4-24) dr (I) sin CL 2 rpW 2 Bc = dQ and 2 (4-23) = dT dr q) cos pW2CL Bc by given are c chord having each blades B containing annulus an on acting torque and thrust incremental The 59 as Now Law. Biot-Savart the of integration direct a is method straightforward most the but equations, differential partial solving by obtained been have element blade a at volocity induced the for solutions Several blade. the of element each at velocities induce filaments vortex trailing the while blade the on lift local the produce to serves voracity bound the scheme, this In accuracy. of loss without neglected be may flow in variation chordwise the solidity, low very have rotors windmill most Since line. vortex a of lieu in sheet vortex bound a by replace be should blade the flow, the represent fully to order In section. blade the over chordwise vary will flow induced the that note may one However, Law. Biot-Savart the via determined be to section each at flow induced the enables scheme simple This line. vortex bound a as modeled is rotor the of blade each wings, to applied as theory vortex of concepts the Following lift. represent to vortices bound of use the involves model frequently-used A disk. actuator optimum the describe to used model flow the from respects many in differs real-rotors over flow The THEORY VORTEX 0.35 .497 1.00 .536 1.73 .418 2.43 .329 10 3.73 .228 7 5.39 .161 5 7.60 .116 4.5 15 20 30 50 27tVcc (i) Bcf/CL Disk Actuator Optimum The For Parameters Blade 4.3 Table 60 propeller. optimum the define to required techniques analytical cover (26) Weinig and (25), Lerbs (24), Theodoresen Betz, of writings The surface. screw rigid a as back move to wake the requires criteria This used. be may (23) criteria Betz the theory vortex using rotor optimum an For velocities. induced calculate and geometry wake assume we here forces calculates and geometry deformation a assumes one where materials of strength elementary in used that to likened be may approach This wake). the in up rolls also (which sheet vortex a as considered be also may propeller a by shed wake the wing), the of downstream distance snort a up roll to happens (which sheet vortex a is wing a from wake the as Just answers. acceptable very gives theory Prandtl's of results the wake, sheet vortex the thru flow which velocities impossible physically calculate can one although and wing the of plane the in lie to assumed is wake the Theory, Lifting-Line Prandtl in Now coupled. are vortices the all unless established be cannot configuration) (or trajectory vortex the other, each on acting each filaments, vortex of array large a of superposition the of consist will wake the Since wake. the in filaments vortex the of trajectory the of knowledge the input an as requires it appear, may method this as straightforward 61 increased. is number blade and ratio speed tip the as cancel will component vorticity streamwise the is, that system; type ring simple a to converge will sides the on system crisscross the that Note 5.2. Figure in shown as appears system wake final the Thus occurs. situation similar a portion forward the across passage On path. the of portion upper the over lift zero assumes it as vortex bound its sheds finally and shown, as pair trailing a and vortex starting a sheds it sector, leeward the up moves blade a As 5.1. Figure in shown is model This path. the to relative attack of angle zero at and velocity constant at path square a follow to constrained are but axis, the about path circular a in move not do these assume simplicity for and blades, lifting slender having machine axis crosswind a consider model, realistic more somewhat a construct To system. ratio speed tip high many-bladed a for model acceptable an be may this that see we Again develops. disc actuator rotor the of that to similar system wake a and shed are device the as section cross of disc actuator oscillating an as simply modeled be to device the assume we if that first note We literature. the in discussed been not has this since actuator, axis crosswind a of system vortex the construct to interest of is it 4.1, Section in discussed approach the Continuing WAKE THE OF MODELING VORTEX 5.1 MACHINES AXIS CROSS-WIND 5 CHAPTER 62 Actuator Axis Cross-Wind of Shedding Vortex 5.1 Figure ION ROTAT OF AXIS V.. WIND 63 uniform. not is flow axial induced the since system, axis wind a of coefficient power ideal the achieve cannot machine cross-axis ideal an even that appears it Thus uniform. not is flow axial internal induced the that and tube the across distributed linearly is vorticity spanwise this that shown be easily can It tube. the within vorticity spanwise internal is there since case previous the from different importantly is This 5.2. Figure in sketched as system vortex wake a obtain now we ratios, advance high assuming and system path square the for used those to similar arguments Adopting changing. continually is vorticity starting and trailing shed the consequently and lift the then axis, fixed a about rotate blades the where system axis crosswind a of case realistic more the consider now we If flow. external zero and flow, axial internal uniform a section, cross circular of one of that as same the is section cross arbitrary of tube vortex infinite an of induction the for solution the that shown be can It Actuator Axis Crosswind Bladed Single of System Vortex 5.2 Figure , ;-1\ 1 .-- , 1 1 , WIND 64 R a sin 2rc --= c CL 0 = CD 0=p assumptions, following the adopt shall we analysis the simplify to order In 5.3. Figure in illustrated system flow the giving a), - V.0(1 velocity has flow incoming the itself device the at then 2aV,o, is perturbation windwise wake the if that obtain we Thus wake. the in value their half one are device the at flows induced the assume will we theory, vortex with Consistent side. the to deflected be can wake the that so force, cross-wind a as well as windwise a experience can devices these general, In forces. wake the to equated be may station each at device the on forces the that sense the in quasi-independently behaves station axis) the to (parallel spanwise each that assume we considered device the For flows. induced the determine to equations sufficient obtains one forces wing and wake the equating By flows. induced unknown contains forces these for expression The itself. surface lifting the at theory airfoil an by as well as wake the of analysis momentum a by system the on forces the express to is which theory, wing of approach standard the adopt we device crosswind-axis Darrieus-type a analyze To ROTOR DARRIEUS 5.2 65 Turbine Crosswind-Axis a for System Flow 5.5 Figure Wind 66 in dO/Q of increment time a spend will airfoil the period, time this Of 27c/Q. is which period one be shall analysis our of interval time the so revolution every itself repeat will process The (5-5) I 0 sin Rd01 = by dO to related is dx width The dO. + 0 position to 0 position angular from goes airfoil the when dx width of be streamtube the Let occupies. airfoil the which streamtube the in lost momentum the to airfoil the on force the equate can we Now (5-4) ij 0) cos 0 sin vavt + 0 sin (v ej sin2 vavt one obtain we p*xf = P (5-3) as expressed be can airfoil the on force the Since a sin 7tcW = (5-2) 2 WCL =F that so (5-1) = pWF = L pW2cCL write can we law, Kutta-Joukowski the with starting and assumptions above the Using stall. near aerodynamics nonlinear the model to analysis numerical requires performance ratio speed tip low The small. is a attack of angle maximum the where ratios speed tip high at analysis inviscid an to limited be then will results Our (5-10) 0 sin2 a)2 is blades B with rotor a for torque average The K20 pncR = Q by given is torque The components. radial and torque into resolved be may force blade the defined, is a that Now (5-9) Kt, 2R sinOI RS2 Bc = a blades B for or (5-8) I 0 sin c RS2 2R Vco a= blade one for a factor interference axial the for expression an yields RO = Vt and a) - V.0(1 = Va that assumption the under forces two these Equating (5-7) 20n a 2K0 a)Ko (1 I sin pRd0 = 0 I dFmomentum as streamtube the in force the yields equation momentum the Now (5-6) dO 0 sin2 2pncVtVa = dFblade as 2760 period time the for equation force blade the write may we 0 ± angles the to respect with symmetrical be to seen is (5-4) equation from contribution force streamwise the Since wake. the of portion rear the in dO/S2 of increment time another and streamtube the of portion front the then is torque drag The R.Q. 68 W is velocity local the that assuming by approximated simple be may losses drag the speeds, tip low at operate not will rotor of type this Since 3. about of ratio speed tip starting a have would radius foot 20 a and chord foot one a with rotor three-bladed a that so Bc (5-14) 1+2 Xstart 4 obtain we max 14° = a. Using tip starting the express to (5-13) equation rearrange may we am to equal set is (5-13) 2R Bc X X am 1 ratio. speed a When a tan where Tr/2 =0 point the at approximately occurs attack of angle maximum The attack. of angle maximum and drag of consideration with made be can refinements Further 0.401. am= = BcX/2R quantity the when 0.554 of coefficient power maximum a yields expression This 32 R2 B2c2X2 3 (5-12) R 37r BcX 4 Bc =7rX Cp by given is coefficient power sectional corresponding the and ) (5-11) 32R (BcX)2 3 R 37T BcX 4 [pnBcRY,20] = Q 69 rotation. of axis the and tangent blade the between 7 angle local the and curve troposkien the illustrates below 5.4 Figure reduced. are lift the of component usable the and speed rotational the both since substantial is rotation of axis the to closer blades the bringing by caused performance on effect The parabola. or curve sine a by approximated is and integrals elliptic by described is curve The troposkien. name the given and (22) Blackwell by investigated been has shape required The tensile. entirely are loads the that so catemary the to similar shape a in blade the deploying by removed be may loads bending These blades. the in loads bending substantial in result and large are loads inertial the rotor, Darrieus-type the for required speeds rotational high the At ROTOR CIRCULAR THE 2 D (5-16) 62 \ CD 4 13n 3 C 3 =C 5.3 Cp that seen be may it and noX = C a3X3 + 2 X 2 16 becomes coefficient power The diameter. disc to circumference blade of ratio the Bc/2R, = 2R (5-15) X3 CDBc -= a as defined be may solidity a p point, this At AC is coefficient power the to contribution the and 2 (5-14) BCX3 pVcc, D 3 C = BcR f2 pR 2 2 2 CD QD (5-18) y 8 3o-2X2CS2 + y cos aX 70 32 % y cos 2pnBcVco = dz dQ is axis rotor the along dz slice a by generated torque The R. of independent is product this since Rmax = R point the at ratio speed tip and solidity the as taken be may crX product the where 0 sin y cos aX = a (5-17) becomes a for expression the rotor, the of height unit a analyze we If 5.2. Section in as manner same the in proceeds rotor curved the of analysis The Length Equal of Caternary and Circle Troposkien, 5.4 Figure R/Rm 0.5 1.0 1.5 , 0.5 Circle Catenary Troposkien 1.0 71 rotor. wind-axis the for developed that to similar theory element blade a of development by model above the in included be can stall and drag of effects The 0.461. = amax = erX at occurs 0.536 of coefficient power maximum a which for blade circular the is case simple one accomplished; be may geometry arbitrary an for (5-19) equation of integration The (5-19) y COS2 8 a2X2 + y cos GX 3n 72--8 y cos R A 4rcaX dzy2pVA 2 ciQ dz p dC is coefficient power incremental the and U 73 height with relation law power a by approximated frequently is terrain rough over flow mean the contrast, By length. Monin-Obukhov the parameter, stability a and roughness surface the velocity, friction surface the parameters, three involved relation Their stratification. unstable and neutral stable, encompasses that flow mean the for relation a developed have (14) Obukhov and Monin terrain flat over layer surface atmospheric the in structure wind of made been have studies Extensive complete. more much is terrain flat over flow of knowledge the contrast By terrain. rough over layer surface atmospheric the in turning wind considerable of presence the reported has (13) Slade turning. wind and spectra turbulence on data no or little is there terrain, rough over flow for exists data gradient wind some While bather. considerable a represents terrain rough of regions in particularly conditions, flow local of knowledge of lack The machines wind to adapted be must variations flow the of effects the of magnitude the predict to techniques secondly, known; be must conditions flow local the First, turbines. wind of operation and design the to difficulties double-edged present all elevation with turning and-wind gustiness gradient, wind Vertical unidirectional. nor steady uniform, neither be will flows Real occur. can motion rotor and irregularities flow both reality, In rotor. the of rotation of plane the to perpendicular be to and parallel and unifoim be to assumed was wind relative the previously, covered rotors of analysis the In INTRODUCTION 6.1 GRADIENT WIND VERTICAL TO DUE MOMENTS AND FORCES 6 CHAPTER 74 coordinates. (t,n) the now are 4 Chapter of (x,y) the Thus XYZ. coordinates the with confusion avoid to order in (t) tangential and (n) normal designated been have element blade a on forces incremental the noted be should it further, proceeding Before significant. is that rotor the of bottom and top the between difference velocity the is it since scale, upon dependent is moments these of magnitude the expected be would As moment. pitching the and variation torque the are these of largest The 6-1. Figure in illustrated as moments and forces induce will gradient wind vertical A GRADIENT WIND VERTICAL OF EFFECTS THE 6.2 I. Appendix in described program the in included are forces and moments flapping (15), Ribner of analysis the using treated be can yaw Rotor moments. and forces large induce can flapping and yaw rotor Both gradient. wind to due loads aerodynamic the with only deal will section This present. are moments and forces mechanical certain moments and forces aerodynamic the to addition In turbine. wind a of operation and design the both hence and dynamics system overall the effect will moments and forces These occur. can moments pitching and forces side dependent time torque, in variations periodic however, output, mean turbine the on effects order first no have previously studied flow the from departures The relation. above the use shall we turbines wind for required is feet) 200 to 100 range limited a over variation wind the that fact the and parameters, fewer requires it since (6-1), equation of simplicity the of Because one. than less is - \hJ (6-1) 11 coefficient the where VR (Z 75 steady- the from generated be can moments and forces order second and first the for Expressions rotation. of angle the with df',1 and dFt force the in variations cause of angle in variation The attack. of angle increased an be increased of effect principle the that seen be may will turn in attack will gust) or gradient it ratios speed tip high to (due velocity At a. attack of angle the and w velocity resultant the both increases Vw in increase The disk. half lower the in blade a for than higher be will velocity axial the disk, rotor the of half upper the in blade a For V. velocity wind local the with replaced been has V. velocity freestream the that in illustrations previous from differs diagram velocity This diagram. velocity blade the illustrates page following the on 6.2 Figure Gradient. Wind a in Rotor 6.1 Figure MOMENT PITCHING AG CI:1)R X TORQUE (6-3) 2 Z2 A 76 T2 + Z TlA + =1T dFt form the in (6-2) equation Rewriting blade. ith the of rotation of angle the to refers Ai where 0i, rsin = AZ distance The elevation. with velocity wind in variation the to due 0) = (Z values hub their from change forces These dFn. for obtained be may expression similar A Vref =u and 2 au dFt , 2 zz 'AZ u +dF, u2 + AZ [dF, z Uz dFtu + 0 au = u dFt aFt a2Ft 2 (6-2) dFt = where dFt that so hub rotor the about Series Taylor a of terms in expressed be may element rotor a on force differential The manner following the in aerodynamics performance state Diagram Velocity Blade -a) I 6.2 Figure ( Vw t 77 NI. of evaluation by approach the indicate us let straightforward, is differentiation of method the As moments. and forces the of magnitude the determine to order in evaluated be to remain T2 and T1 N2, N1, terms The blades. of numbers various for summations the of values the gives page next the on 6.1 Table moment. yawing order second or first no induces gradient wind that noted be may it and evaluated been has blades spaced equally B over summation The odd is B unless (6-6) jdOi dr 2 + fr3N2 i=1 Oi 2N1drIsin2 MOMENT PITCHING i=1 (6-5) s r3T2dr sin2 E fr2Tidr + drirTo = Q TORQUE 2. B where blades, B over summing and blade the over integrating by moments and forces following the obtain we 2 (6-4) +N2 N1AZ + dF=N0 z2 manner same the in dFr, expressing and (6-9) AZ az Z=0 4) au (I)) 78 cos sin2 + CD sin++ cos4)+CL a CL pVRcv 2 = N1 is result final The all (6-8) 13 = (I) La c al a+ aa acL a4) au acL VR As comment. some requires CL of ation differenti The- Z=0 Z (6-7) sinliloauzi CD cos++ )(CL v2 sin3Qt 0 + f(u2 v where rS, and cc + constant remains (z). vw Z=0 au a pA/;'c = AZ = u and 3/2 2 30t cos --- 0 i3 VAT az au = aU a(dFn) N1 i=1 4 0 3 Oi sin3 i=1 4 3 =B 4 =B 0 O1 cos Oi sin2 i=1 cos2Qt 0; sin2 1 2=B Sums Trigonometric 6.1 Table 79 obtained. be may expressions following the that shown be may it drag neglecting by and (1) situ') ratios speed tip high At RELATIONS APPROXIMATE 6.3 obtained. be can approximations form closed case, this In blades. the of portions outer the over constant are c and CL of value the and small is (I) angle the if made be can simplification considerable (6-12), and (6-11) equations from seen be can As moments. and forces other the by obtained are integrals type Similar hub 's (6-12) R tr)4 d(-1.) R R )(1. TC a' + sind)1(1 CD (I) sin CLa sin24))CL + Lk1 r ft = X 12 and R,RR1 (6-11) N 7 C (f3 ar9\ "-hub 'it cc (1)CD cos3 2 (I)CL cos 2 (I)+ sin cl))CL COS2 as evaluated are Z=0 VRdZ2 (6-10) Z=0) +12 dZ VR 12 1.k2 ,j ft = 1 and I integrals the where = CQ A, = Y2pVinR3 QA dVw d2Vw R2 analysis preceding the from evaluated be may coefficient torque in variation The =120' hh Z=0 , 0.14 80 2 dZ VR d2Vw 1 hh 0.104 Z=0 dZ VR dVw 1 yield data wind term long The turbine. wind Smith-Putnam the from data the using by obtained be may values representative Some 4B a) OaCLa 5B (1 crXCL 12 and 2B 2 a (1 GCL where i 2 Z=0 Z=0 i=1 (6-14) 0 BE VR(I7,2 S111 dZ VR +12 R2d2Vw ( 2 \ 1 = 3 TCR pV12(.' RdVw QA CHANGE TORQUE i=1 Z=0 (6-13) Oi sin2 dZ VR RdVw a) 4 La 2 pV127ER M crXC MOMENT PITCHING P 0.4 = C 81 X =Q C , pVircR3 cP 3 2 CQ = Q = pV0TR2 Y2 CT D CT torque. the to moments the and turbine wind the of drag the to forces the reference us let Accordingly, judge. to difficult are numbers The (6-16) Mt) (1cos 0.00153 = TcR3 Y2pV12: QA VARIATION TORQUE (6-15) 20t) (1cos 0.0173 = Y2pV12(.7cR3 MY MOMENT PITCHING machine, Smith-Putnam the of motion flapping the neglecting obtain, we 0.33 = a 5.5 = 0.6 = CL a CL 0.083 = a ft. 87.5 = R 6 =X 2=B below listed values the using and 82 0.17. r yields terrain smooth over flow for evidence Experimental 1/6. = ii when value maximum a has expression This 3. to equal approximately is (6-19) equation in expression bracketed the that noted be may It appreciable. be will scale large for variation torque The C. low and X large have will point design the below speeds wind at RPM constant at operating rotor a example For (6-19). equation from estimated maybe load and solidity ratio, speed tip scale, of effects The hub. rotor the of height the is h where (6-19) ri sin2 +111 a)CL 5(1 4XCL } + 2,92 h 4Cp CQ (112 a)2CLa Xo.(1 obtain we (6-1) equation by given profile aw 1 CQ A power the Adopting change. torque percentage the express to modified be may which change torque the for expression an gives (6-14) Equation discussion. more requires itself variation torque The power. also hence and torque in decrease 4.6% a to up be to seen is variation torque The torque. the of value the of 52% of variation a to amounting appreciable, quite be to seen is moment pitching the while insignificant quite are forces drag and yaw The (6-18) 200 cos (1 =O.023 Q A VARIATION TORQUE 200 cos (1 0.259 (6-17) MOMENT PITCHING 83 4.8. Figure with along 6.3 Figure of results the using by obtained be may gradient to due variation power the of magnitude absolute The example. this in included not was blades the of motion Flapping turbine. wind Smith-Putnam the for gradient wind to due output turbine mean in decrease percentage the illustrates page following the on 6.3 Figure zero. approaches output turbine net the as greatly increases gust) (or gradient wind to due output turbine in variation percentage the that so speed tip with appreciably changes however turbine wind a of output net The ratios. speed tip of range wide a over constant approximately is gradient wind the to due torque in variation The gradient. wind to due output power in change the evaluate to used be also may variation torque the for developed expressions The 14 84 Gradient Wind To Due Output Power In Reduction Percent 6.3 Figure Vco RS/ 12 10 RATIO, SPEED TIP 6 8 4 0 2 4 6 8 10 12 120) z16 (si )1 vi Velocity Wind - 14 Neglected Flapping Blade 813=0° _ Turbine Wind Smith-Putnam 16 85 1972. No.3, 17, Vol. Soc., Helicopter Amer. J. Descents. Steep in Helicopters for Boundaries Ring Vortex of Prediction Analytical J., Wolkovitch, 1955. York, New McGraw-Hill, Engineering, Helicopter of Principles J., Shapiro, 1948. D.C., Washington, 820, Report NACA Yaw, in Propellers S., N. Ribner, 163-187. pp 1954, 24, No. 151, Vol. Trudy, Institut, Geofizicheskii Leningrad, SSSR, Nauk Akademiia from translated Atmosphere, the of Laver Ground the In Mixing Turbulent of Laws Basic M., A. Obukhov, and S. A. Monin, 293-7 p. 1969, April 8, Vol. Meteorology, Applied of Journal H., D. Slade, 1929. 440, p. 123, (A) Proc. Soc. Roy. Propellors, Screw of Theory Vortex the On S., Goldstein, 1919. 193-217, p. Nachr. Gottinger Betz, A. by Energieverlust, gerngstein mit Schraubenpropellor to Appendix L., Prandtl, 1926. 1026, M & R Br, Airscrew, an of States Ring Vortex and Brake Windmill the in Results Experimental of Analysis The H., Glauert, 6, ,1889. 390 p. 30, Vol. Architects, Naval of Institute Transactions, R.E., Froude, 7. 1918. Moscou, de Technique Superieure l'Ecole de Aeronatuiques Essais et Calculs des Bureau du Travanx E., N. Joukowski, 8 543-4. p. 1972, April, No.4, 10, Vol. Journal, AIAA M., P Goorjian, 9 1935. Berlin Springer, Julius 324. p. L, Division 6, Vol. Editor-in-chief), Durand, F. (W. Theory Aerodynamic H., Glauert, 1878. 47, p. 19, Vol. Architects, Naval of Institute Transactions, W., Froude, 1865. 13, p. 6, Vol. Architects, of-Naval Institute Transactions, J., W. Rankine, 1956. York, New Library, Philosophical Power, Wind by Electricity of Generation The W., E. Golding, 1946. 31, January D.C., Washington, PB25370, Board, Production War Development, and Research Production, of Office Turbine. Wind the on Report Final N.Y.U., 1948. York, New Inc. Company, VanNostrand Wind, the From Power C. P. Putnam, References 86 Command. Atl. Air Div. Documents Air Ohio: Dayton, Author. by revised and Luftschraube der Aerodynamik , book, German 1939 from trans. Propeller, the of Aerodynamics 1939/1948, Barth. J.A. Leipzig: Turbomaschinen von Schaufeln die um Stromung Die 1935, F., Weinig, 73-117. 60, Engrs., Marine and Architects Naval Soc. Trans. Circulation," of Distribution Arbitrary an and Blades of Number Finite a with Propellers Loaded "Moderately 1952, W., H. Lerbs, 1948. York, New Inc., Co.; Book McGraw-Hill Propellers, of Theory Theodore, Theodorsen, 68-92. pp. 1943), Bros., Edwards Arbor: Ann (reprint 1927 Gottingen, Betz, A. and Prandtl L. by Aerodynamik und Hydrodynamik zur Abhandlungen Vier in reprinted 193-217; pp. Klasse, Math.-Phys. Gottingen, zu Wiss. der Gesellschaft Kgl. der Nach. Energieverlust," Geringstem mit ler "Schraubenpropel 1919, A., z, Bet Mexico. New Albuquerque, 1974, April, SLA-74-0154, Report Energy Laboratories Sandia Turbine, Wind Vertical-Axis of Type Troposkien a for Shape Blade E., G. Reis, and F., B. Blackwell, 1953. York, New McGraw-Hill, Propulsion, of Aerodynamics Weber, J. and D., Kuchemann, 1973. 10-12, October Alberta, Calgary, Engineers, Agricultural of Society American the of Region Northwest Pacific the of Meeting Annual 1973 the at Presented Canada, Ottawa, Council, Research National the at Developed Turbine Wind Vertical-Axis the of Economics and Performance The R., Rangi, and P. South, 1956. 102, No. Report CoA Cranfield, Windmills. Ducted of Performance and Design the on Report Preliminary A Rainbird, J. W. and M. G. Lilley, 1925. 1014. M & R. A.R.C., Br. Results. Experimental Including Pitch, Small of Airscrews in Applications with Airscrews of Theory Vortex the of Extension An Townend, H. C. H. and Bateman, H. H., N. C. Lock, rotor the at velocity flow Axial area surface projected translator or Rotor radius rotor Local radius Rotor Pressure air the from extracted Power L' length unit per force lift Sectional th rate flow Mass LID ratio, drag to Lift CL coefficient lift Sectional CD coefficient drag Sectional Cx rotation of direction the in coefficient force Sectional Cy rotation' of plane the to normal coefficient force Section Cp or 13/(l/2)pAK3 coefficient, Power D' length unit per force drag Sectional PA1/2)pSVG,3 chord Blade 1-u1N.,, b wake the in factor interference Axial blades of Number A area disc rotor Projected a a rotor the at factor interference Axial a' co/20 -= a' rotor the at factor interference Tangential u/Voc, - 1 Symbols 88 rotor the of downwind velocity angular Fluid velocity angular Rotor density Fluid 6 5, Chapters angle, rotation blade 4; 3, Chapters angle, pitch Blade velocity Translator (i) velocity relative the and rotation of plane the between Angle 11 exponent relation Wind-height 5,6. Chapter angle, pitch blade 2; Chapter velocity, translation the to normal the and wind the between Angle attack of Angle Greek rON., ratio, speed Local R.Q/Vc. ratio, speed Tip X element rotor the to relative velocity Resultant velocity wind stream Free wake the in velocity flow Axial I XICENHddV 89 specified. conditions Operating radius. percent of function a as twist and chord i.e., specified, be must geometry Blade 0012. and 4418, NACA than other if used, section airfoil to conform to rewritten be must NACAXX Subroutine made. changes and/or inputted be must infointation following the geometry propeller given a For changes. program other without placed be can section airfoil any for curvefit a which for subroutine empty an is NACAXX 4418; profile NACA for coefficients drag and lift sectional determines NACA44 subroutine 0012; profile NACA for coefficients drag and lift sectional determines NACA00 subroutines functions; Bessel modified calculates BESSEL subroutine factor; hub-loss the arid factor loss tip the calculates TIPLOS subroutine parameters; related and factors interference angular and axial determines CALC subroutine station; given a at angle twist and chord calculates SEARCH subroutine output; for titles and listing input prints TITLES subroutine functions; output and input integration, performs PROP program main the subroutines: eight with program main a of consists package program The respectively. punch card and printer, line reader, card the to refer program the in 62 and 61, 60, numbers unit Logical systems. other on implementation for differences small some be may there therefore University, State Oregon at package operating OS-3 the under 3300 CDC a using written was It integration. numerical of method pass Rule/three Simpson's a utilizes and language Fortran the in written is package program The PROGRAM LOADS AND PERFORMANCE TURBINE WIND 90 degrees - THETI(I) - HL Prandt - 1 None 0- 1 stations for angle Twist ft (CI(I)) stations dor Chord (I) RR stations for radius Percent - GO None 2Goldstein 1 Prandtl - 0 NACAXX subroutine in be to curvefit Profile - 9999 0012 NACA - 0012 4418 NACA - 4418 - controller mode loss Hub controller model loss Tip NPROF Profile NACA NF specification geometry blade for stations inputted of Number degrees - SI angle Coning ft - H level sea above Altitude 10 original tl seeAppendixII Wilson, AMOD Code Model Interference Axial X ratio speed Tip mph - V velocity Wind B blades of Number degrees - THETP DR angle Pitch incrementation) integration for radius of (percent Percentage Incremental ft - HB ft - R radius Hub blade of Radius are: inputted be to parameters The 91 program. the to changes without profiles other use to user the enables This (degrees). attack of angle of function a as coefficients drag and lift sectional for fit curve a add must one subroutine a is NACA)0( used. be to is NACAXX subroutine means 9999 of input an 4418; profile NACA the for data drag and lift sectional calculate to used be to is NACA44 subroutine means 4418 of input an 0012; profile NACA the for data drag and lift sectional calculates that subroutine a is which used, be to is NACA00 subroutine means 0012 of input An used. be to is method Prandtl's means 1.0 of input an while used, be will model loss hub no means 0.0 of input An model. loss hub the controls it HL; is controller third The used. be to is model loss tip no means 2.0 of input an and model, Prandtl's choose will program the then two, than greater is blades of number the unless used, be to is model Goldstein's means 1.0 input the used, be to is model Prandtl's means 0.0 of input An model. loss tip the determines GO used. be will form root square the means 1.0 of input an while used, be also will form Glauert the means 0.0 of input An used. be will factors interference angular and axial of calculation for method which determines AMOD NPROF. and HL, , GO, AMOD are These -inputted. be must that controllers operation several are There width. character-field 140 of basis the on printed be will Output (I) THETI CI(I) I) RR( NF) Card 4 5 (Card V 81 AMOD X NPROF GO (21-22) NF H HL 4 Card 3 Card B 2 Card TBETP HB DR R 1 Card 41-50 31-40 21-30 11-20 1-10 Columns format: following the in be should Input 92 form. binary to program the convert to desirable be would it desired, are runs many if Therefore, 3300. CDC the on compiled be to seconds ten approximately takes program the that noted, be also should It 10 (4F10.3) FORMAT R,DR,HB,THETP (60,10) READ 10 (4F10.3) FORMAT B,V,X,AMOD (60,10) READ 30 (2F10.3,12,8X,F10.2,14) FORMAT H,SI,NF,GO,NPROF (60,30) READ 40 (F10.3) FORMAT HL (60,40) READ 20 (F5.1,5X,F10.5,F10.5) FORMAT (RR(I),THETI(I),I=1,NF) (60,20) READ used. statements Format and Read input the are following The £6 SS 21C1/(8H-1:1)=NN 95 11=X21 LS (IS)SOD*21=11 (IS)SO3*(EITh-X11)=2113 XII*('JCI-1T)=8111 T+ 65 85 ES 000T/H*170Z000000000 - 6TLE000000'0=SIA (.00001/H*L6Z'O-)dX2*66T69LEZ000=0H21 08T/Id*O1d1V=01d1V 08T/Id*d13H1=d131A1 17S 11/X*A=VOgIAIO '081/Id*IS=IS 009ET08Z9*A=A ZS TS OS 617 817 L17 Si' 0'0=XALA/X 917 90=V 00=d01SV 11' 0.0=X1 0.0=Xb Z17 0'0=AXI4X E17 00=XXV1X 00=.1.MAX 00=Ad 00=A1 -1717 017 SE 0.0=L1 6E 8E LE 9E 00=81 0-0=A?) 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LOT 170Z HZ ZOZ L59 959 559 TO? 00? 661 861 L61 961 S6T 1761 017£ 00E OD (OIC19)91I2JAA 00£ 01 09 (0"0"bg*GOIAIV)dI d0lJdNiV93110(00Z/T9)31IIIM ANITS'H (17SiT9)B1DiN1 X'AiS(ES1T9)31D3M d13H1j8H12101):1 (ZS1T9)31fliM (TS1T9)31IIIM (0SiT9)31DIM £61 MT 161 061 681 881 L81 981 581 1781 £81 Z8T 181 081 A0):IdN'M'T )al'Id1WSIAIOH):1'VD31A10109/IS'WOOLAJVidlaHl'X'AIEVEIH1210121 NOIA11610D (SZ)I131-11'(SZ)IDi(SZ)1111 NOISNANIO Indlno JAIldIliDSgO 5170T 6L1 8LT D D LLT 9L1 SLT 17L1 NVQ:11110A LSO 97 END RETURN C 95 1XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX#) XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX FORMAT(//# 58 70 59 FORMAT(//6X,#MY#,16X,#W#,15X,#Q#,11X,#CT#,13X,#T#,9X,#CP#,13X, 1CX=,9X,#CY=,9X,#FX#,8X,*FY#,12X,MX#) FORMAT(///4X,#R#,10X,#PC-R#,8X,#F,7X,#ALPHA,9X,#CL=,9X,=CD#,9X,# FT=,18X,#FN#) FORMAT(///9X,=A#,14X,#AP*,26X, 200 779 778 659 101 100 320 310 =#,I4) PROFILE #,F20.5,10X,=NACA = RPM FORMAT(//# USED#) MODEL HUBLOSS NO FORMAT(//# PRANDTL#) BY MODELED HUBLOSSES FORMAT(//# USED#) MODEL LOSS TIP NO FORMAT(//# *) FORMULA GOLDSTEINS BY MODELED LOSSES TIP FORMAT(//# #) FORMULA PRANDTLS BY MODELED LOSSES TIP FORMAT(//# USED#) METHOD INTERFERENCE AXIAL STANOARO FORMAT(//# USED#) METHOD INTERFERENCE AXIAL WILSON FORMAT(//# NO#) PHI#,10X,=RE 1#P#,9X, 1HA#) ALP DEGREES -- ATTACK OF ANGLE F#/ -- FACTOR LOSS TIP FORMAT(# -- NUMBER REYNOLDS #/# PHI -- DEGREES -- PHI ANGLE FORMAT(# NC:1#) RE P#) -- KILOWATTS -- POWER CP# -- COEFFICIENT POWER FORMAT(# --T#) LB -- THRUST CT-#/ -- COEFFICIENT THRUST FORMAT(# Q#) -- FT-LB -- TORQUE --W#/# FT/SEC -- VELOCITY RELATIVEC FORMAT(= MY#) -- FT-LB 1-MOMENT-X-DIR/BLADE FORMAT(= - MOMENT-Y-DIR/BLAOE MX#/# -- FT-LB LB - CY#) 71 69 68 67 66 65 1--FY#) FORCE-Y-DIR/BLADE FX=/# -- LB -- FORCE-X-DIR/BLAOE FORMAT(= FOKCE-X-DIR OF COEF FORMAT(# FORCE-Y-DIR OF COEF CX4= 00#) -- COEFFICIENT DRAG CL=/= -- COEFFICIENT LIFT FORM4T(# --FT#) FORCE TANGENTIAL FN4= -- FORCE NORMAL FORMAT(# AP#) FA 64 63 62 169 1CTOR INTERFERENCE ANGULAR A4# -- FACTOR INTERFERENCE AXIAL FORMAT(# PC-R*) -- RADIUS PERCENT R#/# -- FT -- RADIUS FORMAT(# RECORD4///) OUTPUT DATA FORMAT(///////# FORMAT(//5X,F5.1,8X,F10.5,10X,F10.5) 1) ANGLE-DEGREES# RADIUS#,5X,=CHORD-FT=,5X,#TWIST PERCENT FORMAT(///# 1) ==,F7.3,5X,#NUMBER 1ANGLE-DEGREES =#,I2 61 60 57 56 55 SPAN ALONG STATIONS DATA OF LEVEL-FT=#,F10.2,5X,#CONING SEA ABOVE SITE OF ALTITUDE FORMAT(//# =#,F6.3) RATIO SPEED 110X,#TIP =#,F7.2, MPH - VELOCITY =#,F3.0,10X,#WIND BLADES OF NO. FORMAT(/ =,F7.4) DEGREES - ANGLE RADIUS-FT=#,F5.2,10X,=PITCH 110X,A-IUB =#,F6.4, PERCENTAGE RADIUS-FT,F7.2,10X,ANCREMENTAL FORMAT(///# #) RECORD INPUT DATA FORMAT(///# 1INE#) 1045 05/17/74 54 53 52 51 279 278 277 276 275 274 273 272 271 270 269 268 267 266 265 264 263 262 261 260 259 258 257 256 255 254 253 252 251 250 249 248 247 246 245 244 243 242 241 240 239 238 237 236 235 234 233 TITLES 3.12 VERSION FORTRAN 0S3 CIN3 '081/Id*I3H1=1.3H1 (dN)II3H1=13H1 CAN)ID=D 0.17 01 09 017 OE (1-C)I12H1+((T-C)I13H1-(Z-C)I13HIMI3d=13H1 (T-0I3+C(T-0I0-(Z-C)ID)*?Ad=3 UT-01121-(Z-02111)/00T-02111-A21):1)=112d T+I=C 311NIINOD OE OT 01 09 01 09 (AN'bI)AI s3znun II CINV CidOHD (0,01:11:1'39*Al:W)AI 3110INI-1331 N0I1V10dli3INI NVdS 3H1 9NO1V srucivi NDAI9 V SBNIIAI213130 - HDI:IVDS 3HI ZIE i1/LT/S0 ZOE TOE E6Z Z6Z 16Z L8Z 98Z S8Z 3178Z 3E8Z 3 3Nun0bens N0IS:13A 00E 66Z 86Z L6Z 96Z S6Z -176Z OT OZ 06Z 68Z 88Z '001*((IS)S0D*X21)/Th=A111 AN'T=T OZ 00 X2I'Id'1WSIA'01-1):11V9DIA10109/IS'WCIOIAIV`d13HI'X'A'819W1101?1 NO141403 (SZ)II3H1j(SZ)I31(SZ)211:1 NOISN3LAII0 ?3VDNI1 V IV 319NV ISIMI 3H1 (131-11101ANIIIAH1'I3'Til1iTh)H321V3S SNIT Z8Z T8Z 08Z NV2111:10A ESO )39011d BM_ NI C131;101S 66 (IIVA-(II-IcI)SOD*(IHd)NIS*A)/AVA=dV ('elAA+Z**(IHd)NIS*A)/1113A=V X3*DIS*SZT'0=1:1VA 19E 09E 6SE SSE ((A*A-1-219A)*.Z)/((NVD)111OS-A.21E1A*.Z)=V LSE 9SE (11VA'T)/2/VA=dV 85E A3*DIS*5ZT'0=):18A 089 01 SLS OD Li7E (I1-1d)SO3*CID-(IHd)NIS*13=X3 8.17E 0'0=NV3 (0'0'11'NV3)1I (A--T)*A*V3A*17+A*A=NVD C(IHd)SO3*(IHd)NIS*A)/(XD*DIS*SZT.0)=IiVA (Z**(IHd)NIS)/(A3*DIS*SZT.0)=213A SLS 01 OD (O'bTODWV)AI (121*Id)/(3*3)=DIS (IS)SO3*(IHd)NIS'C13+(IS)SO3*(IHd)S03*13 =AD {7SE ESE ZSL ISE OSE 617E 917E (1-11:11IHd'Thili'Id1H10948/A101XXI1XX)S01dI1 11VD S3SSO1 enH C1NV dIl AO Si7E 1717E 3 NOI1V111D1V3 0.0=13 (CZT/Id*7).3D'(VHd1V)SEIV)AI (OCI3'O13IOVHd1VIIS'XIIIII)XXV3VN 11VD (CI3i13IVHd1V'IS'XI:11111)XXVDVN 11VD 008 01 OD (CICI3'O13'CIVHd1V)00VDVN 11V3 (03IDIVHd1V)00VDVN 11V3 008 01 OD (CICIDIC1101CIVHd1V)1717V3VN 11VD (C1D1D'VHd1V)1717VDVN 11VD (.8.I1717 VDVN 3sn -ram VIVI:1901d 31-11 ION 31IAM:Id VDVN V CIBIAIDBdS AAVH noA )1VIts1110A 008 DV11C1 C1NV E17E Zi7E 1i7E 017E OSS 009 6£E 8£E LEE 9EE SEE 1'EE ZEE TEE 009 LEE 0017 (0091T9)31I2IM OSS 01 OD (66662:19.A01:1dN)AI 009 01 00 (ZTOO'bTA01:1dN)AI 01 OD (8T171:7'b3.A01:1dN)AI 6ZE 8ZE LZE 9ZE 0017 SIN3I3IAA303 IAI1 1VNOI1D3S AO NOI1V111D1VD D SZE 17ZE . EZE ZZE TZE TO(T0+VHd1V=CIVHd1V d13H1-131-11-IHd=VHd1V IHA=21IHd Th/11*1XX=01XX (VVIHd)NISAVVIHd)SOD=1XX (IHd)S9V=VVIHd ((lX*(AV-1--T))/(IS)SOD*(V-'T))NVIV=IHd 6TE 81E LIE 171E 0171T-C OT OC1 STE dV=V1-130 V=V1AS 91E LIE ZIE TIE 31-1=1-111 A/V93140*121=1X 81`LI'91'S111711EliZIll'A0ThldN'MT )(21'Id'11-eSIA101-1211VD31n10'0D'IS'WCIONY'd13HI'X'A'8'3W2ICI'll IV sniavb OIL NOIAI1A/OD 'S213131/s1V1iVd 3S31-11 NOdf) IN3C1N3d3C1 SNOTIDN11A S3NI141:1313C1 CINV NJAID V S1101DVA 1:1V111DNV C1NV 1VIXV 31-11 S3NI1Al21319C1 - D1VD 33N3):13AII3INI LOE 3 60E 80E D D 90E SOE (A'VHd1VINV11XidV/VIAD'XD'CIDT 113121IHcli3biAl'AbiAAAIADCAXALAIXIAAA'AXA'13HI'D'111)D1V3 3Nun0bens t7L/LT/S0 St7OT Z £ NOISIGA NV211d0A 170E zoz ESO aNa 1\rdniAll "Z/1:113*(D*17*111*(V--I)*(dV+'T)*T ((IHA)NIS*V1D+(II-Id)NIS*OD-1D*(Z**(IHA)NIS+ I )))+ 81= 81 7/1:10*(D*E**11:1*Z**(V-T)*(V10*(IHA)SOD'ZT +CID*E**(IHA)SOD*.Z-(IHA)NIS*1D*(Z**(IHd)SOD-7)))+LI=L1 1117 9117 ST17 1711' £117 ZI-17 TTfr 9017 6017 :13c1C1(V-. T)*1A+Z1=Z1 1:1DACI*1A+ Ti= T1 1017 IIDAO*Dd*NA+£1=E-1_ 0117 6017 8017 1DACI*1:1DA*(V-. T)*NA+171=171 21DACI*):1Dc:1*(V-I1)*1A+91=91 liDdOIDA*1A+S1=S1 (L'OZAZ`X017)1V141:10d 669 NdilA (669/19)B1n1M 0c1*21D*(V-.T)*((iHd)ANV1V/dAD+AD*"Z)=NA 17017 £017 Z017 1017 0017 ?:IDA*AID*(V-"T)*((IHcOANV1VicIXD+XD*7)=1A XD-(I1-1d)NIS*VCID-1-(IHA)SOD*V13=dAD AD-1-(IHA)SODANCID-(1-1c1)NIS*V1D=c1X0 1OO*0/(0D-OOD)=-VCID 66£ 86£ L6£ Z6£ 16E 06£ 68E (8H-1?:1)*AAA'''dAdlnlX E6E XD*Td*T.LD=AO 176£ AD*11D=d1 96£ 56£ TOO' 0/(1D-C110)=V1D X21/0=1:ID 00:1*.Z)h1C1=1:1DACI (M*M)*(D*El*OHI:1*S*0)=T1D (E1H-111)*AXA=AXAINX AD*1SNOD=AAA XD*1SNOD=AXA (D*(Z**NO*OH11*S.0)=1SNIOD SIA/3*M*OH21.--91:1 D 51101DVA 3DNa213A1:131NDIV1119NV OS ((IHA)NIS)/((IS)SOD*A*(V-. T))=M 88£ L8£ 98E 58£ .178£ CINV 1VIXV NOdfl 11\1gC1N3d30 SNOLLONfld AO NOI1V11131VD D OL 01 09 (I000-31.(dVAN/11213-dVDSEIV)AI OT 311NI1NOD £8£ Z8£ 18E 08£ 61E OS 3DN3911gANOD 110A 1S31 D 81£ ILE 91E SLE (8"51AZ)1V141:10A AV OL ELE ZLE 0£ VLE 09 'V (09/19)31I2:1M 01 09 (1.39.NV)AI TIE S(V11313+c1V)=AV S(V1BEI+V)=V OLE OV 17L/L1/S0 69£ 99E (17-C)AI 19£ OTT/017'0E (0T-OdI 89E 0£'01710£ (ST-0AI 06'017'0£ OTT 59£ 'SN0I1V2131I 2101DVA 331\13113A1131NI IIV1119NV CINV 1VIXV AO NINJdVJV ((IS)SOD*X1:1)/111=2:1Dd 61701 179£ 3 08S £9£ Z9E 31V3 ZI'E N0IS2GA Nt0:11):10A ESO TOT (14V*.Z)/(NV*(T-1,A1V*'Z))=NV 'T+1A1V=IAIV (onv/n)*(2- (on*on-vT)/(mv*on*on))+ziAins=ztAins 00=3 (0.-1.19*LAIV)AI Z (S8Z.T**OCI)/T£0.0=3 Z 01 OD (01.31\l'InIV)AI T (899.**011)/860'0-=3 T ZAT1D - 01 OD (otyaNlAw)i zninm+vms=vms (n*n±-r)/(n*n)=nAd (n*n-FT)/(n*n)-al 9L17 SZt. vti7 £L.17 ZL17 TL17 0L17 69-17 8917 oov (£**ZA)/91+(Z**ZA)41+ZA/Z1+01=ZAT12 t9-14. 9917 (OT**(11*11+'T))/T (OT**11*'9£-8**11*.0917-4-9**11*"590T-17**11*.£09+1411**SG--T)*fl*114:179=9-1. (c**(n*n+-T))/(9**n*'i7 - v**n*-Tz+n*n*17-r--r)*n*n*'9I=i71 v**(n*n-F-T))*n>kn,o7-zi S9.17 17917 £917 00£ 0017 0.1. OD Z917 T917 0917 6917 ZAT1- aId*A*S.)NIS*.Z)/(IV*Id*A)=ZAT1D UZA-C1)*(ZA-D)*(ZA-43)*(ZA-V))/(17**ZZ)+((ZA-D)T 8S-17 SS17 "9*9=0 1S17 9S17 *(ZA-9)*(ZA-V))/(E**ZZ)+((ZA-8)*(ZA-V))/(ZZ*ZZ)+(ZA-V)/ZZ=ZAII '17,07=8 17S17 £S17 (SD2)di 6t717 Z*Z=ZZ OS-17 00£ 01 OD (OIVIA/OZ)13SS3E1 11VD (IViA1Z)13SS2E1 11VD ZS-17 TS17 A*A=ZA aoHlaw L-1717 171717 EIT=LAI OT OC1 Si717 n*on=oz (T-Fwv*z)=A 9t+ EH' SNI31SC11OD 0 Z1717 T1717 00? 01 OD (T000-11*(((IHd)NIS)S9VDdI SOT 01 01 OD OUT OD 00? 996 311NI1NO3 171717 T =A SOT 01 OD (a(T000-+ Z**(IHd)NIS)121bS*121*.Z)/((121-'d)*b)-)dX3)ASODV*(IdtZ)=A HIV 1717t7 OOT (0.Z.b3.0D)dI OD Ot7-17 6E17 8£17 L£17 9£.17 01 OD (0.Z.b3'10D)dI 01 S£17 17£17 ££17 (0.Tb3.0D)dI ZE.17 00? 01 op (olybaoo)di 996 01 00 (C/Z*..1.D.0)I SZ17 wo=nAtris 9n7 cro=vms LZ17 =NV 8Zi7 "T=VILAIV T£17 0E17 6Z17 0.0=1A1V T "sassoi ON AO BSVD 31-11 210d 210 'A2109141 S#11CINV21d 210 1A2103H1 S#NI31S0109 NOdfl CI9SVO EinH C1NV dI1 3H1 S3NI1421319C1 SOldIl - sassoi 17Z.17 £Z17 ZZ.17 3 In' OZ17 ANuncmans (1-121qHd112112:11Id111-110DVA1011`11)SO1dI1 61t7 8T17 Si7O1 ZI*£ N0IS213A NV211210d ES° 17L/LT/S0 CINB Nntru..] Id*d=d ((T000'T +Z**(IHd)NIS)121bS*H1:1*.Z)MHI:1-120*b).-)dX3)dSODV*(IdtZ)=Id 006 SOT 006 01 OD 0-1=U (0'Tb3-1H)dI 005 01 OD T617 osv 6817 88-17. 005 3 SNOIlVinDivD ssmanH L817 9817 S817 17817 E8.17 D Di13,K((no)/(n*n+-0)=d (-r+kivz)hiv=kmv VaLT/S0 SOldIl ZT*£ NOIS'tlgA Ntql1?:10d z8i7 T817 ost. zinins*(idtz)-D=DIED 6LV vms*((id*Id)/13)-(n*n+t)/(n*n)=9 SVOT 8Li7 OT Z.L17 ESO END RETURN AI=((.5*Z)**V)*S CONTINUE C=AK*C S + 30 AK=AK+1. S=B/(C*E) E=P 40 5 TO GO D=D-2. P=D*TK*P 40 TO GO IF(TK.LE.0.0) TK=D-1. P=1. D=V+AK 5 B=(.25*Z*Z)**AK K=1,10 30 DO 1. C= AK=0.0 S=0.0 C MODEL LOSS TIP GOLDSTEIN THE FOR FUNCTIONS BESSEL CALCULATES BESSEL C C BESSEL(Z,V,AI) SUBROUTINE 1045 05/17/74 516 515 514 513 512 511 510 509 508 507 506 505 504 503 502 501 500 499 498 497 496 495 494 493 492 3.12 VERSION FORTRAN 053 END RETURN 25 CD=1.0 25 TO GO IF(CD.LE.1.0) +SD5*(A-AMAX)**4 CD=SD3+SD4*(A-AMAX)**2 CL=0.0 61 TO GO IF(CL.GE.0.0) CL=(AO*A)-(A2*(A-AMAX)**2) 25 TO GO CD=SD0+(SD1+A)+(SD2*A*A) CL=A0*A 24 TO GO IF(A.GT.AMAX) A=ALPHA AMAX=0.218 SD5=12570. SD4=0.0006 SD3=0.0168 SD2=.130 SD1-0.0006 SDO=0.0058 A2=7.*A0 A0=5.73 529. 669,PAGE NO. REPORT NACA IN PUBLISHED DATA NACA OF CURVEFIT POLYNOMIAL ORTHOGNAL A BY OBTAINED WERE EQUATIONS THE AIRFOIL. 0012 NACA A FOR ALPHA; ATTACK, OF ANGLE GIVEN A AT DRAG AND LIFT OF COEFFICIENTS THE DETERMINES - NACA C C C C C C NACA00(ALPHA,CL,CD) SU8ROUTINE 1045 05/17/74 545 544 543 542 541 540 539 538 537 536 535 534 533 532 531 530 529 528 527 526 525 524 523 522 521 520 519 518 517 3.12 VERSION FORTRAN 0S3 0.1851985 0.0248 - - END RETURN - 100 50 10 TO GO 3.23 + -0.11*ALP CL= 60 TO GO IF(ALP.GE,16.0) 10 TO GO 60 CD=+0.0131686686494*ALF +1.934 -0.029*ALP CL= 0.00738*ALP**2 - 0.214377*ALP CL= 50 TO GO GE.15.5) IF(ALP. 30 10 TO GO 0.6078 + 0.0731*ALP CL= 30 TO GO IF(ALP.GE.12.0) 100 TO GO 0.00629752 1+ 0.0000023229*ALP**3 + 0.00002732*ALP**2 + CD=0.0001695356*ALP 100 TO GO 0.000000704*ALP**3 20 10 1+0.00661 0.000028188623*ALP**2 + CD=0.00001644&ALP 10 TO GO IF(ALF.6G.+2.0) 0.3975 + CL=0.099375*ALP 20 TO GO IF(ALP.GE.8.0) ALP=ALPHA*180./3.141593 401. PAGE 824, NO. REPORT NACA IN PUBLISHED DATA NACA OF CURVEFIT POLYNOMIAL ORTHOGNAL A BY OBTAINED WERE EQUATIONS THE AIRFOIL. 4418 NACA A FOR ALFHA; ATTACK, OF ANGLE GIVEN A AT DRAG AND LIFT OF COEFFICIENTS THE DETERMINES - NACA C C C C C C (ALPHA,CL,CD) NACA44 SUBROUTINE 575 574 573 572 571 570 569 568 567 566 565 564 563 562 661 660 559 558 557 556 555 554 553 552 551 550 549 548 547 546 3.12 VERSION FORTRAN 053 1045 05/17/74 00026 SUBPROGRAM. OF LENGTH NACAXX FOR ERRORS NO END RETURN CD AND CL FOR PROGRAM FIT CURVE ADD C ALP=ALPHA*188./3.141593 DEGREES. IN ATTACK OF ANGLE OF FUNCTION A AS COEFFICIENTS DRAG AND LIFT SCCTIONAL FOR EQUATICNS FIT CURVE INSERT MUST ONE STORED. PREVIOUSLY NOT PROFILE A FOR USE FOR SUBROUTINE EMPTY AN IS NACAXX C C C C C C NACAXX(ALPHA,CL,CD) SUBROUTINE 1045 05/17/74 597 585 584 583 582 581 580 579 578 577 576 3.12 VERSION FORTRAN 0S3 II xiaNadav 107 W CL 2 = Frft Kutta-Joukowski from time, same this At blade per = a'rS2 total 4nrF F above calculated circulation the of function a is F circulation the Hence, between. in decreasing and blades the near increasing 0, of function a is a' blades finite For 1 a'r0 47r FtotalB constant. is a' i.e., (0), a' # a' blades of number infinite an For velocity tangent wake = "total {2a1rf2}rd0 2n path circular a Using = 'total ds Hence blades the by "generated" circulation the to equal be must wake the in circulation the conserved, is vorticity Since FACTORS "F" THE OF USE THE y dr c C 2 pW then also, disk rotor the at localized be to "a" Consider -B = a)2a\T,27urdr (1 pVco element dTblade dTmomentum by determined is thrust Now (I) cos sirul) 8F aCx a' 1+ 1 Bc CLW Bc W ID 1+a' (I) cos dp a since sin CL Cx airS2 47trF Combining = dFx cCxdr pW2 , pcVxfdr = (ixd) = d-C)x Since sin(I) CL rT NOW is FL to rtotal of ratio the circulation generated drag the included rtotal a)2 F) - (1. 109 2(S+F2) (1 4SF + VF2 (1) S a.' 2 F = 2S 8sin2 = aCY a= aF)aF (1