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How Does A Car Work?. Chris Paredis G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology. Learn More about Cars. The graphical material in this lecture is copied from www.howstuffworks.com You can find much additional information at this web-site.
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How Does A Car Work? Chris Paredis G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology
Learn More about Cars • The graphical material in this lecture is copied from www.howstuffworks.com • You can find much additional information at this web-site
Car Sub-Systems of Interest Transmission Engine Tires CarBody Torque Converter Differential
Four Cycles Intake Compression Combustion Exhaust
Simplified Engine Model Use SI units! Torque in [Nm], velocity in [rad/s] and Power in [W]
Car Sub-Systems of Interest Transmission Engine Tires CarBody Torque Converter Differential
Torque Converter • The model of a torque converter is fairly complex and highly nonlinear • We 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 Interest Transmission Engine Tires CarBody Torque Converter Differential
Transmission • Purpose: provide large power at all vehicle velocities
Transmission sun planet ring morecompact
Model of a Transmission • Assumptions: • No friction or other losses • No inertia • Reduces the rotational velocity: • Increases the torque where n is the transmission ratio and subscript in refers to the shaft connected to the torque converter.
Car Sub-Systems of Interest Transmission Engine Tires CarBody Torque Converter Differential
Model of a Differential – Same as Transmission • Assumptions: • Car drives in a straight line • No friction or other losses; no inertia • Reduces the rotational velocity: • Increases the torque where n is the transmission ratio and subscript in refers to the shaft connected to the transmission.
Model of a Wheel • Assumptions: • Car drives in a straight line • No 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.
Model of the Car Body • Wind Resistance: • Gravitational Force: • Tire Resistance:
Noise, Vibration, and Harshness Thermal Crash Testing Examples of Other Models in Vehicle Design Computational Fluid Dynamics Stress Analysis