Using CFD to Design the American Challenger Rocket Car

This paper details how computational fluid dynamics (CFD) is being used to design the American Challenger car, under development by Bill Fredrick. This rocket-powered vehicle is intended to set a new world land speed record. Initially, CFD revealed that a biconvex-shape airfoil for the canard and rear strut had advantages over a diamond profile because it limited large-amplitude oscillations caused by transonic shock boundary layer interactions. Later, CFD helped identify proper placement and orientation of the canard and strut to achieve the desired down force and stability. The use of CFD simulations with both propulsion on and off have helped to ensure that the vehicle will have the desired dynamic characteristics at all phases of the record breaking attempts: acceleration, record phase, and deceleration to full stop.