汽车工作原理(英文)HowDoesACarWork

How Does A Car Work?Car Sub-Systems of InterestTorque ConverterEngineTransmissionDifferentialTiresCarBodyEngineFour CyclesIntakeCompressionCombustionExhaustSimplified Engine Model10002000300040005000600070008000050100150200250300350400450Speed RPMPower kWEngine Power as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L10002000300040005000600070008000050100150200250300350400450Speed RPMPower kWEngine Power as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L10002000300040005000600070008000050100150200250300350400450Speed RPMPower kWEngine Power as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L10002000300040005000600070008000050100150200250300350400450Speed RPMPower kWEngine Power as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L10002000300040005000600070008000050100150200250300350400450Speed RPMPower kWEngine Power as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L100020003000400050006000700080000200400600800100012001400Speed RPMTorque NmEngine Torque as a function of Engine SpeedChevy 4-cyl 1.8LFord 6cyl 3LPorsche 8cyl 5.4L()fPUse SI units!Torque in Nm,velocity in rad/s and Power in WCar Sub-Systems of InterestTorque ConverterEngineTransmissionDifferentialTiresCarBodyTorque ConverterTorque ConverterThe model of a torque converter is fairly complex and highly nonlinearWe will not consider it in this class.If you need it,it will be provided to you as a Matlab function.Car Sub-Systems of InterestTorque ConverterEngineTransmissionDifferentialTiresCarBodyTransmission Purpose:provide large power at all vehicle velocities050100150200250300350400050100150200250Velocity kmhPower kWPower at the drive shaft for different gear ratiosTransmissionmorecompactsunplanetringModel of a TransmissionAssumptions:No friction or other lossesNo inertiaReduces the rotational velocity:Increases the torquewhere n is the transmission ratio and subscript in refers to the shaft connected to the torque converter.inoutnoutinnCar Sub-Systems of InterestTorque ConverterEngineTransmissionDifferentialTiresCarBodyDifferentialModel of a Differential Same as TransmissionAssumptions:Car drives in a straight lineNo friction or other losses;no inertiaReduces the rotational velocity:Increases the torquewhere n is the transmission ratio and subscript in refers to the shaft connected to the transmission.inoutnoutinnModel of a Wheel Assumptions:Car drives in a straight lineNo slip;no tire deformation;no friction losses;no inertia Converts rotational velocity into translational velocity:Converts torque into force:where R is the radius of the wheel.carwheelvRwheelcarFRModel of the Car BodyWind Resistance:Gravitational Force:Tire Resistance:21()2dragdcarFCA vsin()gravFmgcos()rollingrFmggravFmgrollingFdragFcos()mgPutting It All Together10002000300040005000600070008000900010000050100150200250300engine speed in rpmtorque in NmEngine and Load Torques for a 10%Slopeengine torqueload torque(1st)load torque(2nd)load torque(3rd)load torque(4th)load torque(5th)Examples of Other Models in Vehicle DesignComputational Fluid DynamicsNoise,Vibration,and HarshnessCrash TestingThermalStress Analysis