Fuel Efficient Engine Package Brittany Borella Chris Jones John Scanlon Stanley Fofano Taylor Hattori and Evan See Project Overview Customer Needs Customer Need Importance ID: 378861
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Slide1
Lightweight
Fuel Efficient
Engine Package
Brittany
Borella
, Chris Jones, John Scanlon, Stanley
Fofano
, Taylor Hattori, and Evan SeeSlide2
Project OverviewSlide3
Customer Needs
Customer Need #
ImportanceDescription
Engine
CN1
1
The engine must reduce fuel consumption when compared to the previous engine package
CN21The engine must provide sufficient power output and acceleration Control SystemCN112The control system must provide accurate fuel delivery and measurement Cooling SystemCN141The cooling system must be able to allow the engine to operate in high ambient temperatures under race conditions Documentation and TestingCN171Documented theoretical test plan and anticipated resultsCN181Must provide a CFD analysis of the intake manifold, restrictor, and throttleCN192Must provide an accurate model of the engine in GT-suiteSlide4
Engineering Specifications
Spec. #
ImportanceSource
Specification (metric)
Unit of Measure
Marginal Value
Ideal Value
Comments/StatusS11CN1Fuel Consumptionkm/l6.9 8.3Want to use ~0.7 gal for the 22km runS3
1
CN2
Power OutputHP4555 S41CN2Torqueft-lbs3135 S61CN4,15Reliabilitykm50100Should be able to perform in all Formula SAE events and testing before major overhaulS81CN6Weightlbs7568Engine weight S91CN8Fuel TypeN/A E85 Ethanol-Gasoline Blend or 100 Octane GasolineS121CN14Temperature°F220 200Cooling system must keep the engine under 200 degrees in ambient temperatures up to 100 degreesSlide5
Engine ModelSlide6
Air/Fuel Ratio: 0.86 LambdaSimplified tubular geometry used for initial induction and exhaust modelsCRF250R valve flow scaled until WR450F data is measuredWiebe combustion model parameters currently estimated until cylinder pressure data is obtainedIgnore effects of muffler
Surface roughness values estimatedWall heat transfer properties estimated for steel exhaust sectionsIntake and exhaust valve lift estimated from YZ400F until actual measurements can be madeAssume constant operating temperature and component temperatures—to be correlated with dyno dataAssume ambient conditions of 14.7
psia and 80°F Overall AssumptionsSlide7
Finalized intake/throttle/restrictor geometryFinalized injector placement(s)Injector flow dataIntake/exhaust valve inflow and outflow loss coefficientsIntake/exhaust cam profilesBase cam timingGeneral cranktrain dimensionsSurface area ratios for head and pistonsP-V Diagrams to validate
Wiebe model assumptionsVarious temperature measurements
Required ParametersSlide8
Theoretical Engine ModelSlide9
Live Simulation of Engine ParametersSlide10
Dynamometer Test StandSlide11
Cylinder Head Removed for MeasurementSlide12
Photo Courtesy of
DUT RacingBore Tube Production
Flow Testing of Cylinder HeadSlide13
System Test PlanSlide14
Engine CharacterizationTorqueP-V DiagramsBrake Specific Fuel ConsumptionCooling SystemSensorsCylinder PressureCrank angleThermocouples
Fuel FlowCoolant FlowBasic Engine DiagnosticsWideband Lambda
Engine TestingSlide15
FT-210 SeriesGems Sensors & Control0.026 - 0.65 gal/min± 3% Accuracy
Fuel Flow SensorSlide16
PCB PiezotronicsTransducer 112B10422E In-Line Charge Converter
Cylinder Pressure SensorSlide17
AM4096 - 12 bit rotaryMeasure Angular PositionOutputsIncrementalSeries SSILinear VoltageAnalogue Sinusoidal
Magnetic EncoderSlide18
Load SimulationPower CharacterizationFuel/Spark Mapping
DynamometerSlide19
Dynamometer ControllerData Input ImprovementNI PCI-6024E200 kS/s12-Bit16-Analog-Input DAQ
Data AcquisitionSlide20
CFD AnalysisSlide21
20 mm inlet diameter (19 mm for E85) creates choked flow conditions, limiting total mass airflow to engineRequired by competition rulesKeeps engine power at a safe level for competitionDesign goal is to minimize loss coefficient through restrictor geometry to allow maximum airflow into engineSupersonic Converging – Diverging Nozzle Geometry
Expand out diverging section to allow for proper shock development to minimize loss coefficientKeep diffuser angle low enough to avoid potential flow separationKeep overall length low to reduce viscous losses due to surface friction and boundary layer growth
Intake RestrictorSlide22
2-Dimensional Axis-Symmetric analysis allows for fast solving time with refined mesh in areas of shock development
Intake RestrictorSlide23
Air flows from throttle to engine intake port through intake manifoldIntake PlenumActs as air reservoir for engine to draw air from during intake strokePrimary purpose is to damp out pressure pulses from intake stroke to create steady flow conditions at the restrictorIntake RunnerPath through which engine pulls air from the plenum into the combustion chamber during intake strokeLength decided by harmonic frequency at various engine operating speeds, can be used to create a resonant “tuning point”
Intake ManifoldSlide24
Transient Pressure Boundary Condition used to simulate pressure pulses within manifold from intake strokePiecewise-Linear Approximation used for initial analysis trouble-shootingEnd analysis will use pressure trace measured during Dynamometer Testing
Intake ManifoldSlide25
Component SimulationShroud structure analyzed to ensure uniform airflow distribution across radiator face and verify proper mass airflow through radiatorRadiator modeled as a material resistance with heat addition and flow re-direction to properly simulate airflow through core
Cooling System AirflowSlide26
Full Car Simulation to verify shroud is receiving adequate airflowSimulation model still in progress, needs additional geometry and refinement
Cooling System AirflowSlide27
Cooling SystemSlide28
Cooling System Schematic
Surge Tank
Overflow Tank
Steam from Cylinder Head
Engine Block
Water Pump
Fan
Radiator
ThermostatSlide29
Rule of thumb: 1.1 in2 radiator surface area needed per hp producedTherefore need approx. 66 in2Radiator from YFZ450R Yamaha ATV7.5” 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
Radiator
Outlet to Water Pump
Inlet from Engine
Modify for bleed line to Surge TankSlide30
Coolant naturally builds to approximately 16-18 psiNormal production cars run 16-18 psi, high performance cars run 22-24 psi , and racing systems run 29-31 psiPressurizing 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° F10 PSI239° F20 PSI259° F
30 PSI
273° F
40 PSI
286° F
50 PSI297° F Radiator CapSlide31
Typically a 1 quart containerNeed 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 tank½” – ¾” Refill line from bottom of surge tank to inlet of water pumpBenefits – de-aeration2% 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!
Surge Tank
Bleed line inlet from radiator and cylinder head
Outlet to overflow tank
Refill line back to water pump
30 PSI Pressurized Radiator CapSlide32
Comes stock on engineNo internal bypass system. Thermostat will have to regulate continual water flow through engine¾” ID inlet and outlet tubing to connect to radiator
Water Pump
Flow Rate vs. RPM from R6 water pump
Need to test flow rate once we have the cylinder head againSlide33
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 temperatureThis 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
Thermostat
Stewart/Robert Shaw Thermostats
– 302
Augments
b
ypass system
$14.95Slide34
Cooling System Data
Reviewed three sets of autocross runs with different driversSlide35
Verify radiator is receiving adequate airflow at low speedsSPAL Axial Fan11” Dia.755.0 CFMBased on predicted power require minimum 450 CFMBased on airflow at speed available require minimum 500 CFM
Maximum 7” Dia. to fit radiatorYamaha R6 Fan5.5” Dia.Est. >500 CFM
Fan
Q = required heat rejected into air
Slide36
Risk AssessmentSlide37
Risk Assessment - Technical
ID
Risk ItemEffect
Cause
L
S
I
Action to Minimize RiskOwnerTechnical Risks1Engine Dynamometer not reliableUnable to characterize engine torqueDynamometer control system not reliable224Be familiarized with the Dynamometer control programs. Attempt to characterize the Dynamometer and create an accurate control system in case the original is inefficient. Stanley Fofano 3Insufficient Cooling of the Engine
Engine Overheats/damage to engine
Cooling system undersized or inefficient
236Correctly analyze cooling system to maximize efficiencyEvan See, Brittany Borella4Unable to accuractly predict airflow through the intake manifold, restrictor, and throttleInaccurate theoretical model of engineImproper CFD analysis224Accurately control initial assumptions and conditions in order to create the most accurate model possibleTaylor Hattori5Unable to accurately predict fuel consumption and power outputInefficiencies in the engine packageImproper Engine Modeling236Verify engine model with dynamometer testing in correlation with fuel flow sensors.John Scanlon8Air:Fuel Ratio too leanDamage to engineRatio leaned out too far in order to increase fuel economy236Slowly change the air fuel mixture in order to realize effects before another change is madeChris Jones, John ScanlonSlide38
Risk
Assessment - Management
IDRisk Item
Effect
Cause
L
S
IAction to Minimize RiskOwnerProject Management Risks10Insufficient fundingOutside contracted work won't be able to be paid forOutside Contracting work is expensive111Use funds wisely and try to do as much in house testing as possible. When outside testing is necessary, try to take advantage of sponsorships.Brittany Borella11Inconsistant Team Priorities
Actual Senior Design deliverables do not get met
Actual engineering in the project given more priority than Senior design paperwork and deliverables
111Project Manager(s) in charge of keeping track of all deliverables, for the class and the actual engine design, and making sure they are being taken care of by everyone on the teamEvan See, Britttany Borella12Project not completed on timeFormula team does not have a complete engine packagePoor time management and planning133Lead engineer will make sure that sufficient time is put into all engine systems so that all components are properly tested and prepared for the final engine packageJohn Scanlon13Parts are ordered too lateEngine Dyno testing and on car testing cannot be completed on timelong lead parts not identified and ordered on time122Long lead time parts ordered as soon as identified - early in MSD1John Scanlon