High Performance Computing: A Mathematical Aerodynamic Model for Vehicle Driving Simulations

Abstract Aerodynamic lift force can affect automobile handling characteristics and wind gust can affect vehicle directional stability. Experimental measurements of the drag forces are usually made for fuel economy estimation and hence do not cover large wind angles that are important for vehicle stability studies of wind gust or extreme maneuvers. The Virtual Aerodynamic Wind Tunnel (VAWT) which uses PowerFlow is an ideal numerical tool in the early vehicle design stage to provide the aerodynamic forces from a vehicle model. The numerical technique is also advantageous over experimental measurements because it does not need a hardware prototype and the computer model is relatively easier to set up for design iterations. Since the dynamic effects of aerodynamic forces on a vehicle and its driver are best studied with a driving simulator in a real time environment, the VAWT calculated air drag coefficients are reduced to a mathematical function suitable for the real time driving simulations. Available test measurements are used to ensure the practicability of the mathematical function. A vehicle model is then used to test the aerodynamic model and study the effects of the aerodynamics on the vehicle directional stability.