SCHOOL OF ENGINEERING DIPLOMA IN MECHANICAL ENGINEERING PRACTICAL LAB 1 REPORT EXPERIMENT 1: LOSSES IN PIPING SYSTEMS APRIL 2024 SESSION Course Code Course Title Learning Assessed : : : EGR 2183 Fluid Mechanics CLO 3 - Perform Fluid Mechanics experiments according to Standard Operating Procedures Group Name Team Member : : 1 2 3 Group 2 *Submission Date/Test Date : Lecturer Total Mark : : Feedback : Name ASSESSMENT Instructor’s Signature : Matric No. Table of Contents 1.0 Introduction ........................................................................................................................ 3 1.1 Introduction of Internal Flow of Piping ..............................................................................3 1.2 Type of Fluid Flow ..........................................................................................................3 1.3 The Entrance Region .......................................................................................................4 1.4 Losses of Flow in Pipes....................................................................................................5 2.0 Objectives................................................................................................................................. 6 3.0 Theoretical Background ......................................................................................................... 6 4.0 Methodology ............................................................................................................................ 7 5.0 Results ...................................................................................................................................... 8 6.0 Discussion................................................................................................................................11 6.1 The head loss in the fluid between the 3/8” vs 1/2" PVC pipe. ............................................. 11 6.2 The effects of volume flow rate on the head loss, ππ³ in a fluid. ............................................ 12 6.3 Experimental vs. Theoretical head loss, ππ³ in the fluid. ...................................................... 13 6.4 Factors that caused Percentage Error and Solution ............................................................ 13 7.0 Conclusion ............................................................................................................................. 14 8.0 References .............................................................................................................................. 15 9.0 Appendix-A ...................................................................................................................... 16 10.0 Appendix-B..................................................................................................................... 18 1.0 Introduction 1.1 Introduction of Internal Flow of Piping Liquid or gas flow through pipes or ducts is commonly used in heating and cooling applications and fluid distribution networks. The fluid in such applications is usually forced to flow by a fan or pump through a flow section. There is friction which directly related to the pressure drop and head loss during flow through pipes and ducts. Pressure drop is used to determine the pumping power requirement. (Yunus A.Cengel and John M.Cimbala, 2014) Figure 1: Pipes (Ubuy, 2012) Figure 2: Duct (librarykeeda, 2020) A typical piping system involves pipes of different diameters connected to each other by various fittings or elbows to routes the fluid, valves to control the flow rate, and pumps to pressurize the fluid. (Yunus A.Cengel and John M.Cimbala, 2014) Figure 3: Valve (RS, 1937) Figure 4: Pump (KOKENT, 1990) 1.2 Type of Fluid Flow Fluid flow in three possible regimes: a) Turbulent Flow A dynamic and chaotic type of fluid flow characterized by irregular motion and the formation of eddied, vortices, and fluctuations in velocity and pressure. It occurs at high velocities, low viscosity, and in the presence of disturbances or obstacles, playing a significant role in many natural and engineered systems. (BYJU'S, 2011) Figure 5: Turbulent Flow (physics world , 2017) b) Laminar Flow Figure 6: Laminar Flow (Mad Laboratory, 2008) A smooth and orderly type of fluid flow characterized by parallel layers of fluid particles moving without significant mixing. In laminar flow, the particles move in a predictable manner, following well-defined streamlines. It occurs at low velocities, high viscosities, and in the absence of obstructions, creating an organized and predictable flow pattern. (BYJU'S, 2011) c) Transitional Flow A type of fluid flow that occurs between laminar and turbulent flow regimes. It exhibits a mixture of laminar and turbulent characteristics, with the flow pattern oscillating between the two states. It is influenced by factors such as flow velocity, fluid viscosity, and pipe roughness, making it a transitional phase in fluid behavior analysis. (BYJU'S, 2011) Figure 7: Transitional Flow (Google , 2024) 1.3 The Entrance Region The region of flow in which the effects of the viscous shearing forces caused by fluid viscosity are felt is called the velocity boundary layer or just the boundary layer. The hypothetical boundary surface divides the flow in a pipe into two regions: ο· ο· Boundary layer region, The viscous effects and the velocity changes are significant Irrotational flow region. The frictional effects are negligible and the velocity remains essentially constant in the radial direction Figure 8: Development of The Velocity Boundary Layer in a Pipe The thickness of this boundary layer increases in the flow direction until the boundary layer reaches the pipe center and thus fills the entire pipe, as shown in Figure 8, and the velocity becomes fully developed a little farther downstream. The region from the pipe inlet to the point at which the velocity profile is fully developed is called the hydrodynamic entrance region, and the length of this region is called the hydrodynamic entry length. Flow in the entrance region is called hydrodynamically developing flow since this is the region where the velocity profile develops. The region beyond the entrance region in which the velocity profile is fully developed and remain unchanged is called the hydrodynamically fully developed region. The flow is said to be fully developed when the normalized temperature profile remains unchanged as well. Source: (Yunus A.Cengel and John M.Cimbala, 2014) 1.4 Losses of Flow in Pipes There are two types of losses which could happen during the flow in pipes: ο· ο· Major Losses The major losses of energy are due to friction effect between the moving fluid and the walls of pipe. Minor Losses The losses due to disturbances in flow pattern or due to change in velocity are called as minor losses. These losses may occur because of the sudden change in the area of flow and the direction of flow. These losses are less as compare to major losses. The minor loss of the energy includes the following cases: i. Loss of energy because of sudden enlargement ii. Loss of energy because of sudden contraction iii. Loss of energy at the entrance of a pipe iv. Loss of energy at the exit of a pipe v. Loss of energy because of bend vi. Loss of energy in various pipe fittings vii. Loss of energy because of obstruction Source: (ROHINI COLLEGE OF ENGINEERING & TECHNOLOGY , 2007) 2.0 Objectives ο· ο· ο· Measure and analyse friction or pressure loss (differential pressure) across various pipes, fittings, and valves in a piping system. Determine the discharge coefficient for flow measuring devices. Investigate the relationship between flow rate, pipe diameter, and head loss in the turbulent region, and compare theoretical values with experimental results to assess accuracy and identify potential sources of error. 3.0 Theoretical Background There are several equations that might be used in this experiment. ο· The head loss for pipe flow problems, β = π , where f is friction factor, L is length of pipe, D is diameter of pipe, V is velocity of fluid flow, g is gravitational acceleration. ο· Friction loss for laminar flow, π = , where Re is the Reynold’s Number. ο· Friction loss for turbulent loss, = −1.8 log[ Ι / D is the relative roughness. ο· Minor head loss, β = πΎ , where KL is the resistance coefficient. / . . + . ] , where 4.0 Methodology Preparation: 1. Connect the hydraulic bench to the piping loss apparatus. 2.Adjust valves to control flow. 3.Purge air bubbles from the system. 4.Ensure the apparatus is ready for the experiment. Experiment Procedure: 1.Open the flow control valve to allow water to flow through the desired pipeline. 2.Adjust water flow rate using the pressure control valve. 3.Measure and record the flow rate using a water meter and stopwatch. 4.Open corresponding pressure taps to measure pressure loss across pipes or fittings/valves. 5.Record the pressure readings using a differential pressure gauge. 6.Repeat the experiment at different flow rates and for different pressure tapings as specified in the experimental data sheet. 7.Record the flow rates and pressure readings for each experimental condition. 5.0 Results Room Temperature: 25° c Table 1: Experimental data with respect to different diameter of pipe. Type Volume, V (πΏ) Time, t (s) Flow Rate, Q (L/s) β (actual) (m) π£ (m/s) Re [-] f (pipe) [-] πΎ (valve or fitting) [-] β (theory) (m) Percentage Difference (%) 0.7963 Differential gauge pressure difference, βπ (kPa) 7 PVC 1/2” (ID=17mm, L=1.25m) 47.78 60 0.7136 3.5082 66935 0.01984 - 0.9153 22.0365 39.71 60 0.6618 6 0.6116 2.9157 55630 0.02060 - 0.6564 6.8251 31.38 60 0.5230 4 0.4077 2.3042 43963 0.02165 - 0.4308 5.3621 PVC 3/8” (ID=13.9m m, L=1.25m) 47.78 60 0.7963 15 1.5291 5.2474 81863 0.01919 - 2.3996 36.2769 39.71 60 0.6618 11 1.1213 4.3611 68035 0.01972 - 1.7190 34.7702 31.38 60 0.5230 7 0.7136 3.4465 53766 0.02084 - 1.1346 37.1093 Globe Valve 3/4” (ID=20.9m m) 47.78 60 0.7963 50 5.0968 2.3211 54446 - 15.00 4.1189 23.7417 39.71 60 0.6618 31 3.1600 1.9290 45248 - 15.00 2.8448 11.0798 31.38 60 0.5230 16 1.6309 1.5245 35760 - 15.00 1.7768 8.2114 90deg Elbow 3/4” (ID=20.9m m) 47.78 60 0.7963 1 0.1019 2.3211 54446 - 1.75 0.4805 78.7929 39.71 60 0.6618 1 0.1019 1.9290 45248 - 1.75 0.3319 69.2979 31.38 60 0.5230 0 0 1.5245 35760 - 1.75 0.2073 100 Graph of Volume flow rate against Head Loss in the 1/2" PVC Pipe 1.0000 0.9153 0.9000 Head Loss,hL (m) 0.8000 0.6564 0.7000 0.7136 0.6000 0.5000 0.6116 0.4308 0.4000 0.3000 0.4077 0.2000 0.1000 0.0000 0.5000 0.5500 0.6000 0.6500 0.7000 Volume Flow Rate,Q (L/s) Theoretical 0.7500 0.8000 0.8500 Experimental Figure 9: Graph of volume flow rate against head loss in the 1/2” PVC pipe. Graph of Volume flow rate against Head Loss in the 3/8" PVC Pipe 3.0000 2.3996 Head Loss,hL (m) 2.5000 2.0000 1.719 1.5291 1.5000 1.1346 1.0000 1.1213 0.7136 0.5000 0.0000 0.5000 0.5500 0.6000 0.6500 0.7000 0.7500 0.8000 Volume Flow Rate,Q (L/s) Experimental Theoretical Figure 10: Graph of Volume flow rate against head loss in the 3/8” PVC pipe. 0.8500 Graph of Volume flow rate against Head Loss in the 3/4" Globe Valve 6.0000 5.0968 Head Loss,hL (m) 5.0000 4.0000 3.16 4.1189 3.0000 1.7768 2.8448 2.0000 1.6309 1.0000 0.0000 0.5000 0.5500 0.6000 0.6500 0.7000 0.7500 0.8000 0.8500 Volume Flow Rate,Q (L/s) Theoretical Experimental Figure 11: Graph of Volume flow against head loss in the 3/4" Globe Valve. Graph of Volume flow rate against Head Loss in the 3/4" 90 deg Elbow 0.6000 0.4805 Head Loss,hL (m) 0.5000 0.4000 0.3319 0.3000 0.2073 0.2000 0.1019 0.1019 0.1000 0 0.0000 0.5000 0.5500 0.6000 0.6500 0.7000 0.7500 0.8000 Volume Flow Rate,Q (L/s) Theoretical Experimental Figure 12: Graph of Volume flow against head loss in the 3/4" 90deg Elbow. 0.8500 6.0 Discussion 6.1 The head loss in the fluid within the 3/8” vs 1/2" PVC pipe. As shown in the Figures 9 and 10, when comparing both graphs, the peak value of the experimental Head Loss,β in the 1/2" Pipe pipe (Inner Diameter of 17 × 10 π) with the value of 0.7136m is significantly lower than that of the 3/8” PVC pipe (Inner Diameter of 13.9 × 10 π ) with the value of 1.5291m. This difference is attributed to the head loss being affected by the viscosity of the dynamic fluid (water), and the wall shear stress of the PVC pipe (Yunus A.Cengel and John M.Cimbala, 2014). It is important to note that both Reynold number of the 1/2" and the 3/8” exceed the critical value of 4000, indicating that the flow of the fluid (horizontally) within these PVC pipes is turbulent. Overall, there are two main factors that can be easily manipulated and closely related to each other, that affected the value of head loss in this experiment: Darcy friction factor, f and Diameter of the pipe, D. a. Darcy Friction Factor, f: According to the Colebrook equation, the co-relationship between the friction factor, f and the ratio of the roughness to the pipe’s internal diameter, , and the Reynold number, Re can be determined for a turbulent flow. This equation is stated as below: 1 6.9 π ≅ −1.8log [ +( ). ] π π 3.7π· π From a mathematical analysis perspective, the Darcy Friction Factor, f is inversely proportional to both the ratio of the mean height of the roughness of the pipe to the pipe diameter, , and the Reynold Number, Re. At large Reynold Number, the friction factor, f is a minimum for a smooth pipe and increases with its roughness. This indicates that as the diameter decrease, the ratio of roughness to diameter will decrease, and the friction factor will increase for a turbulent flow (Yunus A.Cengel and John M. Cimbala, 2014). (This can refer to the Appendix-B item No.1). Moreover, according to the Darcy-Weisbach equation, the Head Loss, β , is directly proportional to the friction factor, f. Thereof, the high value of friction factor, induced by the pipe’s rough internal surface and high Reynolds number, will increase the wall shear force in the pipe, in which the shear stress’ direction is opposite to the fluid. Over a certain area in contact, this high resistance factor resulting in a greater shear force exerted by the fluid against the inner wall of the PVC pipe (πβπππ πππππ, π = ππ΄). This indicates that more energy losses due to the shear force (also can be refer as friction) as it moves along the pipe. Overall, the head loss is greater in 3/8” PVC pipe. b. Diameter of the Pipe, D: In this experiment, in which the fluid’s properties are remain constant, the 3/8” PVC pipe with a smaller diameter (13.9mm) indeed have a higher ratio of the mean height of roughness to the pipe diameter ( ), which in turn causes a relatively higher value of friction factor (f), and thus inducing a higher value of head loss, β in the flowing fluid within the PVC pipeline. The comparison between 3/8” and 1/2" PVC pipes are stated as below: ο· ο· 3/8” PVC pipe: smaller diameter, D means higher velocity for a specific flow rate, Q, leading to more friction and higher head loss, β . 1/2” PVC pipe: larger diameter, D allows for slower velocity for a specific flow rate, Q, resulting in less friction and lower head loss, β . Technically, the increases/decreases in head loss in a fluid can be influenced by several factors such as volume flow rate, pipe length, and pipe diameter. For PVC pipes, as the diameter decreases, the head loss, β increases due to a reduction in the cross-sectional area through which the fluid can flow. This means that for the same flow rate, the fluid will move faster in a smaller diameter pipe and resulting in higher friction and thus greater head loss. 6.2 The effects of volume flow rate on the head loss, ππ³ in a fluid. Figure 9 presents both the experimental and theoretical values related to specific volume flow rates under control. Our observations indicate that the head loss, β , increases with the rising volume flow rate of the fluid within the pipe’s internal region. This suggests that higher flow rates contribute to an increase in the fluid’s head loss. According to the Poiseuille’s law: π=π π΄ = β where Q is volume flow rate, π is dynamic coefficient of viscosity of the fluid, and D is the Inner diameter of the pipe. Given that the diameter of the 3/8” PVC pipe and the dynamic coefficient of viscosity remain constant, the variation in volume flow rate, Q corresponds to a change in the average velocity of the fluid per unit of time (second). This alteration in average velocity can be attributed to the adjusted power of the water pump. Due to the fact that the shear force impact, π, that is induced by the viscosity of the fluid, acting on the inner wall of the pipe, is always opposite in direction of the flow of the fluid. This force is the result of the fluid’s viscosity, which creates internal friction as the fluid layers move relative to each other. This shear force is responsible for the “drag force” that opposes the motion of the fluid, leading to the pressure drops in pipe flow and thus inducing the head loss in the fluid. Overall, the high average velocity of the dynamic fluid within the PVC pipe will induces a high-volume flow rate, which in turn increases the head loss, β of the fluid. Moreover, the volume flow rate, Q, is directly proportional to the quartic of inner diameter of the PVC pipe. This is because the increase in head loss with higher flow rates is a result of the greater frictional forces acting against the horizontal movement of the fluid, which are indeed more pronounced at higher velocities (Yunus A.Cengel and John M.Cimbala, 2014). When the diameter of the PVC pipe increases, the volume flow rate increases, thereby inducing a greater value of head loss, β in the fluid. These changing variables are monitored and systematically represented in the graphical illustrations inside Figures 9, and 10. 6.3 Experimental vs. Theoretical head loss, ππ³ in the fluid. The experimental and theoretical values of head loss, β in the fluid are presented in Table 1. These data are monitored and controlled by specific volume flow rate of the fluid within the pipeline. At a flow rate of 0.7963 L/s, the head loss percentage difference for various type of pipe/fitting/valve are recorded as follows: 22.0365% for a 1/2" PVC pipe, 36.2769% for a 3/8” PVC pipe, 23.7417% for a Globe valve, and a significant 78.7929% for a 3/4" 90-degree elbow fitting. When the flow rate decreases to 0.6618 L/s, the percentage differences adjust to 6.8251% for the 1/2" PVC pipe, 34.7702% for the 3/8” PVC pipe, 11.0798% for the Globe valve, and 69.2979% for the elbow fitting. At an even slower rate of 0.5230 L/s, the differences are 5.3621% for the 1/2" PVC pipe, 37.1093% for the 3/8” PVC pipe, 8.2114% for the Globe Valve, and a complete deviation of 100% for the elbow fitting. Across the various flow rates tested, the 3/4" 90-degree elbow fitting consistently exhibits the highest deviation between experimental and theoretical head loss, β values. 6.4 Factors that caused Percentage Error and Solution There are several factors that can caused the experimental values deviates from the theoretical head loss in the fluid such as inconsistency data displayed by the flow rate indicator, inaccurately data displayed by the pressure gauge meter, turbulent flow, and partial closed valve in the fluid system. 1. Inconsistency data displayed by the flow rate indicator. The inconsistency data displayed by the flow rate indicator will result in an unreliable measurement of the flow rate of the fluid within the PVC pipeline. It also increases the toughness for us to calculate the flow rate for the fluid accurately. As a result, it will lead to significant deviations between the experimental and theoretical head loss, β values. 2. Inaccurately data displayed by the pressure gauge meter. The inaccurately date displayed by the pressure gauge meter resulted from the presence of the air inside the branch connection pipe to the pressure gauge meter. This will result in inaccurately data generated by the pressure gauge meter. Consequently, the experimental head loss will deviate from the theoretical one. 3. Turbulent flow. The disorderly and rapid fluctuations of swirling region inside the turbulent flow can causes significant fluctuations in the values of velocity, temperature, and pressure (Yunus A.Cengel and John M. Cimbala, 2014). This is because the instantaneous velocity component is the sum of average velocity of the fluid and a fluctuating component velocity. Consequently, it results in the total amount of shear stress in a turbulent flow is the sum of two different component shear stresses: shear stress in laminar flow and shear stress in turbulent flow. As a result, any random eddy motion of the turbulent flow will cause unexpected changes in pressure, and the velocity of the flow. This will affect the accuracy of the data being collected. (Yunus A.Cengel and John M. Cimbala, 2014) 4. Partial closed valve in the fluid system. The partial closed valve will significantly increase head loss within the fluid system. This occurs when the turbulent eddies that are produced in the valve and continue downstream. These eddies led to some mechanical energy consumption, due to the energy is dissipated into heat in the downstream pipe flow. This phenomenon explained the huge pressure difference observed in global valve. (Yunus A.Cengel and John M. Cimbala, 2014) Eventually, it will affect the experimental head loss values. 5. Solutions: To minimize these experimental errors, the experiment should be conducted in a more careful way. Firstly, the average volume flow rate of the fluid should be considered and multiply with the calibration factor that is set by the manufacturer. Apart from that, the air from the connection branch pipe should be removed entirely to avoid inaccuracy/sensitivity of the pressure meter. Besides, the volume flow rate should be adjusted carefully to minimize the eddies motion in the turbulent flow. Lastly, ensure that the valve closed completely to avoid turbulent eddies being produced below the valve and the downstream within the pipeline. 7.0 Conclusion In conclusion, this experiment proven that the diameter of the pipeline, volume flow rate of the fluid does contribute to reduction/increment of the head loss in the fluid system. When the properties of the fluid such as temperature and density remain constant, the head loss in the fluid changes correspond to the specific volume flow rate, Reynold number, viscosity of the fluid, and friction factor. It is important to note that the flow can be classified into laminar and turbulent. For our experiment, the flow in all types of the components is said to be turbulent as the Reynold number exceeds 4000. Therefore, it is expected that the friction factor is high when the flow is in a smaller diameter pipe. This results in high average velocity of the flow and eventually increases eddies motion in turbulent flow. These random fluctuations indeed caused unexpected rise in head loss in the fluid. Therefore, 3/8” PVC pipe has the second highest deviation between the experimental and theoretical head loss values. However, in the case of highest deviation between experimental and theoretical head loss in the 90-degree elbow fitting, the pressure drops inaccurately due to the flow separation, which it can be improved by reducing the change of direction instead of sharp turn. Overall, this experiment fulfils the expectation of the theoretical value as the percentage difference capped at the ranged of 5.3621% to 37.1093% for the horizontal flowing fluid within the PVC pipeline. 8.0 References BYJU'S, 2011. Types of Fluid Flow. [Online] Available at: https://byjus.com/gate/types-of-fluid-flow/ [Accessed 3 May 2024]. Google , 2024. transitional flow. [Online] Available at: https://www.google.com/search?q=transitional+flow&sca_esv=46dfe222c76fb569&sca_upv=1&udm=2 &biw=786&bih=658&ei=q6Q0Zp3IEqaOseMP7f6hEA&ved=0ahUKEwjdyZutjPGFAxUmR2wGHW1_ CAIQ4dUDCBA&uact=5&oq=transitional+flow&gs_lp=Egxnd3Mtd2l6LXNlcnAiEXRyYW5zaXRpb25 hbCBmbG9 [Accessed 3 May 2024]. KOKENT, 1990. PEDROLLO PUMP ENERGY SAVE 22000W 1000~6000L/MIN 35~15M F100/160A. [Online] Available at: https://www.kokent.com.my/product/pedrollo-pump-energy-save-22000w-10006000lmin3515m-f100160a/ [Accessed 3 May 2024]. librarykeeda, 2020. What is ducting/Types of ducting/ thickness of GI duct sheet/How to calculate the area of ducting?. [Online] Available at: https://www.librarykeeda.com/2020/07/what-is-ductingtypes-of-ducting.html [Accessed 3 May 2024]. Mad Laboratory, 2008. Laminar Flow Leapfrog Fountain. [Online] Available at: https://madlaboratory.wordpress.com/2008/05/23/laminar-flow-leapfrog-fountain/ [Accessed 3 May 2024]. physics world , 2017. Is turbulent flow universal after all?. [Online] Available at: https://physicsworld.com/a/is-turbulent-flow-universal-after-all/ [Accessed 3 May 2024]. physicsworld, 2017. Is turbulent flow universal after all?. [Online] Available at: https://physicsworld.com/a/is-turbulent-flow-universal-after-all/ [Accessed 3 May 2024]. ROHINI COLLEGE OF ENGINEERING & TECHNOLOGY , 2007. 4.5 MAJOR AND MINOR LOSSES OF FLOW IN PIPES , Tamil Nadu, India: ROHINI COLLEGE OF ENGINEERING & TECHNOLOGY . RS, 1937. RS PRO Stainless Steel Full Bore, 2 Way, Ball Valve, BSPP 2in. [Online] Available at: https://my.rs-online.com/web/p/ball-valves/7644278 [Accessed 3 May 2024]. Ubuy, 2012. White PVC Pipe - Custom Length - 1.5 Inch Sch40. [Online] Available at: https://www.ubuy.com.my/en/product/FEOKONK-pvc-pipe-sch40-1-1-2-inch-1-5-whitecustom-length-1ft [Accessed 3 May 2024]. Yunus A.Cengel and John M. Cimbala, 2014. Chapter 8.5 Turbulent flow in pipes. In: Fluid MechanicsFundamentals and Application Third Edition. New York,US: McGraw-Hill, p. 362. Yunus A.Cengel and John M. Cimbala, 2014. Chapter 8.5- Turbulent Flow in Pipes. In: Fluid MechanicsFundamentals and Application Third Edition. New York,US: McGraw-Hill, p. 368. Yunus A.Cengel and John M. Cimbala, 2014. Chapter 8.6 Minor Losses. In: Fluid MechanicsFundamentals and Application Third Edition. New York,US: McGraw-Hill, pp. 374-375. Yunus A.Cengel and John M.Cimbala, 2014. Chapter 8.1 Introduction. In: Fluid MechanicsFundamentals and Application Third Edition. New York, US: McGraw-Hill, p. 362. Yunus A.Cengel and John M.Cimbala, 2014. Chapter 8.3 The Entrance Region. In: Fluid Mechanics Fundamentals and Application Third Edition. New York, US: McGraw- Hill, p. 362. Yunus A.Cengel and John M.Cimbala, 2014. Chapter 8.4 Laminar Flow in Pipes- Pressure Drop and Head Loss. In: Fluid Mechanics-Fundamentals and Applications Third Edition. New York,US: McGraw-Hill, pp. 355-356. 9.0 Appendix-A a. Volume Flow Rate, Q: For 1/2" PVC Pipe, π = π= 47.78 60 π = 0.7963 πΏ/π b. Experimental Head Loss (actual),ππ³ : β = ππ βπ For 1/2” PVC pipe, the change in pressure is 7kPa. β = (1000)(9.81) 7000 β = 0.7136π c. Average velocity of the flow, ππππ : π =π΄ ×π£ For 1/2" PVC pipe, its cross-sectional area, π΄ needs to be determined first. π΄ = ππ· 4 π΄ = π(17 × 10 ) 4 π΄ = 2.2698 × 10 π π£ = π π΄ Do note that the unit of Q needs to be in cubic meter. (0.001 factor) 0.7136(0.001) 2.2698 × 10 π£ = π£ = 3.5082π/π d. Reynold Number, Re: π π = ππ£ π· π Where π is density, D is Inner diameter of pipe, and π is he dynamic coefficient of viscosity. For 1/2" PVC pipe, at which the average velocity, π£ π π = is 3.5082m/s: (1000)(3.5082)(17 × 10 ) (0.891 × 10 ) π π = 66935 e. Darcy Friction Factor, f: For 1/2" PVC pipe, the Reynold Number exceeds 4000, the flow is turbulent. In addition, roughness, π of the PVC is equal to 0.0015mm. 1 6.9 π ≅ −1.8log [ +( ). ] π π 3.7π· π 1 6.9 0.0015 × 10 ≅ −1.8log [ +( ) . ] 66935 (3.7)(17 × 10 ) π π = 0.01984 f. Theoretical Head Loss (theory),ππ³ : For 1/2" PVC pipe: β =π πΏπ£ π· 2π β =(0.01984) ( . × . )( ( . ) ) β = 0.9153π g. Percentage Difference, πΉ (%): πΏ= π£ −π£ π£ × 100% where π£ is experimental value and π£ is theoretical value. For 1/2" PVC pipe, πΏ= 0.7136 − 0.9153 × 100% 0.9153 πΏ = 22.0365% 10.0 Appendix-B 1.
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