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Formula 1Formula 1Group Members: Group Members:
Quinn CollettQuinn CollettSteve GodlewskiSteve Godlewski
Tobiah HalterTobiah HalterJeff SwansonJeff Swanson
Academic Advisor:Academic Advisor:Dr. Chien WernDr. Chien Wern
June 4, 2003June 4, 2003
IntroductionIntroduction
Formula SAE is a competition focused on Formula SAE is a competition focused on the design and fabrication of an the design and fabrication of an affordable, weekend racecar. affordable, weekend racecar. Performance and reliability are necessary Performance and reliability are necessary attributes. attributes.
As a Senior Project group we chose to As a Senior Project group we chose to design three major components of the design three major components of the car. car.
Project ScopeProject Scope
Design, fabrication and testing of the Design, fabrication and testing of the three design components:three design components: Hub AssembliesHub Assemblies DrivetrainDrivetrain AerodynamicsAerodynamics
Decision ProcessDecision Process
Product Design SpecificationsProduct Design Specifications External SearchExternal Search Internal SearchInternal Search Concept EvaluationConcept Evaluation
Presentation OutlinePresentation Outline
Rear Hub and Upright DesignRear Hub and Upright Design Front Hub and Upright DesignFront Hub and Upright Design Differential Housing and Drivetrain Differential Housing and Drivetrain
DesignDesign Aerodynamics DesignAerodynamics Design
Rear Hub and Upright DesignRear Hub and Upright Design
ComponentsComponents Bearing Housing Bearing Housing FlangesFlanges Connection PointsConnection Points Angle BracketAngle Bracket Bearings Bearings FastenersFasteners
Analysis of HubAnalysis of Hub Material: 6061-T6 AluminumMaterial: 6061-T6 Aluminum Yield Strength: 40 ksiYield Strength: 40 ksi Factor of Safety: 3Factor of Safety: 3 Design Stress: 13.3 ksiDesign Stress: 13.3 ksi
Results of FEA Analysis:Results of FEA Analysis: Max Von Mises Stress: 14.5 ksiMax Von Mises Stress: 14.5 ksi Maximum Displacement: 0.002 inMaximum Displacement: 0.002 in
Analysis of Analysis of UprightUpright
Material: 6061-T6 AluminumMaterial: 6061-T6 Aluminum Yield Strength: 40 ksiYield Strength: 40 ksi Factor of Safety: 3Factor of Safety: 3 Design Stress: 13.3 ksiDesign Stress: 13.3 ksi
Results of FEA AnalysisResults of FEA Analysis Max stress: 16.3 ksiMax stress: 16.3 ksi Max Deflection: 0.004 inMax Deflection: 0.004 in
VerificationVerificationPDS CriteriaPDS Criteria WeightWeight: :
The hub assembly will weigh less than 17 lbs.The hub assembly will weigh less than 17 lbs. Hub=2.5 lb, Upright=4.5 lb, Total = 7 lbHub=2.5 lb, Upright=4.5 lb, Total = 7 lb
Size/shapeSize/shape: : Components will fit within an 13 inch wheel.Components will fit within an 13 inch wheel. It does fit.It does fit.
MaintenanceMaintenance: : 2 hour yearly overhaul2 hour yearly overhaul Maintenance free: sealed bearings, locktite on all screwsMaintenance free: sealed bearings, locktite on all screws
InstallationInstallation: : Install in less than 120 min.Install in less than 120 min. Can be done inside of an hour: press in bearings, 3 bolts per sideCan be done inside of an hour: press in bearings, 3 bolts per side
Cost Cost (materials, bearings, bolts): (materials, bearings, bolts): less than $400less than $400 Housing: $54.00, Hub: $186.94, Flange: $65.20, Connectors: $50.54, Housing: $54.00, Hub: $186.94, Flange: $65.20, Connectors: $50.54,
Angles: $1.34, Fasteners: $8.61, Bearings: $18.80Angles: $1.34, Fasteners: $8.61, Bearings: $18.80 Total Cost of Materials: $385.43Total Cost of Materials: $385.43
Dynamic TestingDynamic Testing Has performed properly to this pointHas performed properly to this point
Front Hub/UprightFront Hub/Upright Design CriteriaDesign Criteria
PDSPDS 30%-40% weight reduction over last years car30%-40% weight reduction over last years car Ideal weight of 14 lbs.Ideal weight of 14 lbs. Assembly fit within a 13 in. dia. WheelAssembly fit within a 13 in. dia. Wheel Handle loadings in race conditionsHandle loadings in race conditions Incorporate connecting points for suspension and steering Incorporate connecting points for suspension and steering
systemssystems
Component SelectionComponent Selection Suspension GeometrySuspension Geometry Steering PositioningSteering Positioning Brake ComponentsBrake Components Bearing SelectionBearing Selection
Front Hub/UprightFront Hub/Upright
AnalysisAnalysis CalculationsCalculations Track ConditionsTrack Conditions
Top speeds 60 mph/ Avg. Speed 30 mphTop speeds 60 mph/ Avg. Speed 30 mph
Safety FactorsSafety Factors
Front Hub/UprightFront Hub/Upright ComponentsComponents
Hub assemblyHub assembly Two piece design for ease of Two piece design for ease of
maintenancemaintenance Double row angular contact Double row angular contact
bearing ( axial and radial bearing ( axial and radial loads)loads)
UprightUpright SpindleSpindle
Modeled using Modeled using SolidworksSolidworks®® Used to ensure fitUsed to ensure fit
Compatibility with other Compatibility with other componentscomponents
Clearances and interferenceClearances and interference
Front Hub/UprightFront Hub/Upright
MaterialsMaterials 6061-T6 Aluminum6061-T6 Aluminum 304 Stainless Steel304 Stainless Steel
ManufacturingManufacturing CNC MillCNC Mill LatheLathe PressPress
Front Hub/UprightFront Hub/Upright
VerificationVerification WeightWeight
Last years 32 lbs. This year Last years 32 lbs. This year 11.4 lbs. 11.4 lbs.
64% weight reduction64% weight reduction Under Ideal weight of 14 Under Ideal weight of 14
lbs.lbs. Track testingTrack testing
Handles loads under Handles loads under acceleration, deceleration, acceleration, deceleration, and corneringand cornering
Problems/ImprovementsProblems/Improvements Two Piece SeparationTwo Piece Separation SpacersSpacers Further Advanced Further Advanced
OptimizationOptimization Weight reductionWeight reduction Cost reductionCost reduction
DrivetrainDrivetrain
Use of Common Use of Common PartsParts Honda CBR 600 F1Honda CBR 600 F1 Limited Slip Limited Slip
DifferentialDifferential
Use of Common Use of Common MaterialsMaterials 4140 Steel4140 Steel 6061-T6 Aluminum6061-T6 Aluminum
Rear DifferentialRear Differential
Aluminum HousingAluminum Housing Zexel Torsen Limited Zexel Torsen Limited
Slip DifferentialSlip Differential
Sealed BearingsSealed Bearings Retain Gear OilRetain Gear Oil
Check ValveCheck Valve Roll-Over and Tilt Roll-Over and Tilt
ProtectionProtection
Power TransmissionPower Transmission
Axle ShaftsAxle Shafts 4140-3/4” Steel4140-3/4” Steel U-JointsU-Joints
Drive ShaftDrive Shaft Splined DriveSplined Drive Chain and SprocketChain and Sprocket
Rear Mono-BrakeRear Mono-Brake
Drive Train VerificationDrive Train Verification
PerformancePerformance Dyno-TestinigDyno-Testinig Road TestingRoad Testing
WeightWeight Target 50 lbsTarget 50 lbs
Manufacturing TimeManufacturing Time Target 15 hoursTarget 15 hours
Production CostProduction Cost Target $2000Target $2000
FailuresFailures Drive Axle WeldsDrive Axle Welds Shielded BearingsShielded Bearings
Changes?Changes?
Acceleration Torsion Acceleration Torsion TestingTesting
Aerodynamics & BodyAerodynamics & Body
Modeled using 3-D software Modeled using 3-D software package, SOLIDWORKS®package, SOLIDWORKS®
Forms CNC machined Forms CNC machined Allowed for precision forming Allowed for precision forming
and exact fitand exact fit
Material: 1/8” fiberglass mat w/ Material: 1/8” fiberglass mat w/
fine mat finishfine mat finish Light weight and durableLight weight and durable
Total Weight: 8.5 lbs. Total Weight: 8.5 lbs. Significantly below PDS targetSignificantly below PDS target
Body & Aerodynamics Body & Aerodynamics con’t…con’t…
Lift and Drag Coefficients (as effected by ground promimity)
0
0.050.1
0.150.2
0.250.3
0.35
0 0.05 0.1 0.15
h/L
Co
eff
icie
nt
Drag Coefficient
Lift Coefficient
Estimated drag coefficient (CEstimated drag coefficient (CDD), front lift coefficient (C), front lift coefficient (CLL), drag force (D) and lift force (L)), drag force (D) and lift force (L) CCDD = 0.14 = 0.14 D = 1.950 lbfD = 1.950 lbf CCLL = 0.15 = 0.15 L = 0.910 lbfL = 0.910 lbf
© 1992 SAE
Body & Aerodynamics Body & Aerodynamics con’t…con’t…
Estimated skin drag coefficient (CEstimated skin drag coefficient (CFF) and surface shear force per unit ) and surface shear force per unit
surface area (surface area (ττ) ) (friction resistance)(friction resistance) CCFF = 4000 = 4000 ττ = 901.87 lbf/ft = 901.87 lbf/ft22
Source: Race Car Engineering, Katz
Body & Aerodynamics Body & Aerodynamics con’t…con’t…
Overall Performance EvaluationOverall Performance Evaluation Overall weight of car significantly minimizedOverall weight of car significantly minimized
PDS projected weight = 30 lbPDS projected weight = 30 lb Actual weight = 8.5 lb Actual weight = 8.5 lb
Dimensions of car w/in 2% of desiredDimensions of car w/in 2% of desired
Drag force minimized as specified in PDSDrag force minimized as specified in PDS Typical F-1 CTypical F-1 CD D = 1.07= 1.07 PSU Formula CPSU Formula CD D = 0.015= 0.015
Lift force acceptable but could be further minimized by introducing further Lift force acceptable but could be further minimized by introducing further down force components which were sacrificed to make room for critical down force components which were sacrificed to make room for critical components (i.e. intake apparatus, radiator)components (i.e. intake apparatus, radiator)
Typical F-1 CTypical F-1 CL L = -0.99= -0.99 PSU Formula CPSU Formula CL L = 0.015= 0.015
Cooling performance maximized by channeling air over water-cooled Cooling performance maximized by channeling air over water-cooled componentscomponents
average engine temperature w/o channeled air over radiator = 220average engine temperature w/o channeled air over radiator = 220°F°F average engine temperature w/ channeled air over radiator = 200°Faverage engine temperature w/ channeled air over radiator = 200°F
Performance in ActionPerformance in Action