Lightweight Fuel Efficient Engine Package Brittany Borella, Chris Jones, John Scanlon, Stanley Fofano, Taylor Hattori, and Evan See Project Overview Customer Needs Customer Need # Importance Description Engine CN1 1 The engine must reduce fuel consumption when compared to the previous engine package CN2 1 The engine must provide sufficient power output and acceleration Control System CN11 2 The control system must provide accurate fuel delivery and measurement Cooling System CN14 1 The cooling system must be able to allow the engine to operate in high ambient temperatures under race conditions Documentation and Testing CN17 1 Documented theoretical test plan and anticipated results CN18 1 Must provide a CFD analysis of the intake manifold, restrictor, and throttle CN19 2 Must provide an accurate model of the engine in GT-suite Engineering Specifications Spec. # Importance Source Specification Unit of Marginal (metric) Measure Value Fuel km/l 6.9 Consumption Ideal Value Comments/Status 8.3 Want to use ~0.7 gal for the 22km run S1 1 CN1 S3 1 CN2 Power Output HP 45 55 S4 1 CN2 Torque ft-lbs 31 35 S6 1 CN4,15 Reliability km 50 100 Should be able to perform in all Formula SAE events and testing before major overhaul S8 1 CN6 Weight lbs 75 68 Engine weight S9 1 CN8 Fuel Type N/A S12 1 CN14 Temperature °F 220 200 E85 Ethanol-Gasoline Blend or 100 Octane Gasoline Cooling system must keep the engine under 200 degrees in ambient temperatures up to 100 degrees Engine Model Overall Assumptions Air/Fuel Ratio: 0.86 Lambda Simplified tubular geometry used for initial induction and exhaust models CRF250R valve flow scaled until WR450F data is measured Wiebe combustion model parameters currently estimated until cylinder pressure data is obtained Ignore effects of muffler Surface roughness values estimated Wall heat transfer properties estimated for steel exhaust sections Intake and exhaust valve lift estimated from YZ400F until actual measurements can be made Assume constant operating temperature and component temperatures—to be correlated with dyno data Assume ambient conditions of 14.7 psia and 80°F Required Parameters Finalized intake/throttle/restrictor geometry Finalized injector placement(s) Injector flow data Intake/exhaust valve inflow and outflow loss coefficients Intake/exhaust cam profiles Base cam timing General cranktrain dimensions Surface area ratios for head and pistons P-V Diagrams to validate Wiebe model assumptions Various temperature measurements Theoretical Engine Model Live Simulation of Engine Parameters Dynamometer Test Stand Cylinder Head Removed for Measurement Flow Testing of Cylinder Head Bore Tube Production Photo Courtesy of DUT Racing System Test Plan Engine Testing Engine Characterization Torque P-V Diagrams Brake Specific Fuel Consumption Cooling System Sensors Cylinder Pressure Crank angle Thermocouples Fuel Flow Coolant Flow Basic Engine Diagnostics Wideband Lambda Fuel Flow Sensor FT-210 Series Gems Sensors & Control 0.026 - 0.65 gal/min ± 3% Accuracy Cylinder Pressure Sensor PCB Piezotronics Transducer 112B10 422E In-Line Charge Converter Magnetic Encoder AM4096 - 12 bit rotary Measure Angular Position Outputs Incremental Series SSI Linear Voltage Analogue Sinusoidal Dynamometer Load Simulation Power Characterization Fuel/Spark Mapping Data Acquisition Dynamometer Controller Data Input Improvement NI PCI-6024E 200 kS/s 12-Bit 16-Analog-Input DAQ CFD Analysis Intake Restrictor 20 mm inlet diameter (19 mm for E85) creates choked flow conditions, limiting total mass airflow to engine Required by competition rules Keeps engine power at a safe level for competition Design goal is to minimize loss coefficient through restrictor geometry to allow maximum airflow into engine Supersonic Converging – Diverging Nozzle Geometry Expand out diverging section to allow for proper shock development to minimize loss coefficient Keep diffuser angle low enough to avoid potential flow separation Keep overall length low to reduce viscous losses due to surface friction and boundary layer growth Intake Restrictor 2-Dimensional Axis-Symmetric analysis allows for fast solving time with refined mesh in areas of shock development Intake Manifold Air flows from throttle to engine intake port through intake manifold Intake Plenum Acts as air reservoir for engine to draw air from during intake stroke Primary purpose is to damp out pressure pulses from intake stroke to create steady flow conditions at the restrictor Intake Runner Path through which engine pulls air from the plenum into the combustion chamber during intake stroke Length decided by harmonic frequency at various engine operating speeds, can be used to create a resonant “tuning point” Intake Manifold Transient Pressure Boundary Condition used to simulate pressure pulses within manifold from intake stroke Piecewise-Linear Approximation used for initial analysis trouble-shooting End analysis will use pressure trace measured during Dynamometer Testing Cooling System Airflow Component Simulation Shroud structure analyzed to ensure uniform airflow distribution across radiator face and verify proper mass airflow through radiator Radiator modeled as a material resistance with heat addition and flow re-direction to properly simulate airflow through core Cooling System Airflow Full Car Simulation to verify shroud is receiving adequate airflow Simulation model still in progress, needs additional geometry and refinement Cooling System Cooling System Schematic Overflow Tank Surge Tank Steam from Cylinder Head Thermostat Water Pump Radiator Fan Engine Block Radiator in2 Rule of thumb: 1.1 radiator surface area needed per hp produced Therefore need approx. 66 in2 Modify for bleed line to Surge Tank Inlet from Engine Radiator from YFZ450R Yamaha ATV 7.5” H x 11.5” W x 7/8” D Surface Area 86.25 in2 Inlet and Outlet ¾” ID tubing to connect to water pump Outlet to Water Pump Radiator Cap Coolant naturally builds to approximately 16-18 psi Normal production cars run 16-18 psi, high performance cars run 22-24 psi , and racing systems run 29-31 psi Pressurizing the water allows for the water to reach a higher temperature before boiling (therefore vaporizing) Part# T30R Radiator Cap 29-31 PSI Pressure (PSI) Boiling Point (° F) 0 PSI 212° F 10 PSI 239° F 20 PSI 259° F 30 PSI 273° F 40 PSI 286° F 50 PSI 297° F Surge Tank 30 PSI Pressurized Radiator Cap Typically a 1 quart container Need to modify the part of the Radiator that currently has the cap and overflow line to run a ¼”- 3/8” bleed line from radiator to top of surge tank ½” – ¾” Refill line from bottom of surge tank to inlet of water pump Bleed line inlet from radiator and cylinder head Outlet to overflow tank Benefits – de-aeration 2% air in the system leads to an 8% decrease in cooling efficiency 4% air in the system leads to a 38% decrease in cooling efficiency! Refill line back to water pump Water Pump Comes stock on engine Need to test flow rate once we have the cylinder head again No internal bypass system. Thermostat will have to regulate continual water flow through engine ¾” ID inlet and outlet tubing to connect to radiator Flow Rate vs. RPM from R6 water pump Thermostat Placed at the outlet of the engine, a thermostat allows water to circulate through the block, but doesn’t allow this water to circulate through the radiator until it has reached proper operating temperature This temperature (195°F) melts the “wax motor”, which forces the thermostat piston to open and allows the water to flow through. If the engine’s temperature is lowered too much, the piston closes until it has reached proper operating temperature once again Stewart/Robert Shaw Thermostats – 302 Augments bypass system $14.95 Cooling System Data Reviewed three sets of autocross runs with different drivers Fan Verify radiator is receiving adequate airflow at low speeds 11” Dia. 755.0 CFM Based on predicted power require minimum 450 CFM Based on airflow at speed available require minimum 500 CFM mph 0 5 10 15 20 25 30 35 40 SPAL Axial Fan Maximum 7” Dia. to fit radiator Yamaha R6 Fan F19 ft^3/m 0 213 426 639 853 1066 1279 1492 1705 F20 ft^3/m5 0 130 260 391 521 651 781 912 1042 𝑞 = 𝑚 × ∆𝑇 × 𝑐𝑝 𝑄 𝑐𝑓𝑚𝑟 = ∆𝑇 5.5” Dia. 𝑐𝑓𝑚𝑟 = 𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 𝑎𝑖𝑟𝑓𝑙𝑜𝑤 𝑓𝑟𝑜𝑚 𝑓𝑎𝑛 Est. >500 CFM Q = required heat rejected into air Risk Assessment Risk Assessment - Technical ID Risk Item Effect Cause L S I Action to Minimize Risk Owner Technical Risks 1 Engine Dynamometer not reliable Dynamometer control system not reliable 2 2 4 3 Engine Cooling system Insufficient Cooling of Overheats/damag undersized or the Engine e to engine inefficient 2 3 6 Unable to accuractly Inaccurate predict airflow through Improper CFD 4 theoretical model the intake manifold, analysis of engine restrictor, and throttle 2 2 4 2 3 6 5 Unable to accurately predict fuel consumption and power output 8 Air:Fuel Ratio too lean Unable to characterize engine torque Inefficiencies in the engine package Improper Engine Modeling Damage to engine Ratio leaned out too far in order to increase fuel economy 2 3 6 Be familiarized with the Dynamometer control programs. Attempt to characterize the Dynamometer and create an accurate control system in case the original is inefficient. Correctly analyze cooling system to maximize efficiency Accurately control initial assumptions and conditions in order to create the most accurate model possible Verify engine model with dynamometer testing in correlation with fuel flow sensors. Slowly change the air fuel mixture in order to realize effects before another change is made Stanley Fofano Evan See, Brittany Borella Taylor Hattori John Scanlon Chris Jones, John Scanlon Risk Assessment - Management ID Risk Item Effect Cause L S I Action to Minimize Risk Owner Project Management Risks 10 Outside contracted Insufficient Outside Contracting work won't be able funding work is expensive to be paid for 11 Actual engineering in Actual Senior Inconsistant the project given more Design Team priority than Senior deliverables do not Priorities design paperwork and get met deliverables 1 1 Formula team Project not does not have a Poor time management 12 completed on 1 complete engine and planning time package 13 Engine Dyno Parts are long lead parts not testing and on car ordered too identified and ordered testing cannot be late on time completed on time 1 1 Use funds wisely and try to do as much in house testing as possible. When outside testing is necessary, Brittany Borella try to take advantage of sponsorships. 1 1 Project Manager(s) in charge of keeping track of all deliverables, for the class and the actual engine Evan See, design, and making sure they are Britttany Borella being taken care of by everyone on the team 3 Lead engineer will make sure that sufficient time is put into all engine 3 systems so that all components are John Scanlon properly tested and prepared for the final engine package 2 2 1 Long lead time parts ordered as soon as identified - early in MSD1 John Scanlon