Techniques for Aerodynamic Analysis of Cornering Vehicles 2015-01-0022
When a vehicle travels through a corner it can experience a significant change in aerodynamic performance due to the curved path of its motion. The yaw angle of the flow will vary along its length and the relative velocity of the flow will increase with distance from the central axis of its rotation. Aerodynamic analysis of vehicles in the cornering condition is an important design parameter, particularly in motorsport. Most racing-cars are designed to produce downforce that will compromise straight-line speed to allow large gains to be made in the corners. Despite the cornering condition being important, aerodynamicists are restricted in their ability to replicate the condition experimentally. Whirling arms, rotary rigs, curved test sections and bent wind tunnel models are experimental techniques capable of replicating some aspects of the cornering condition, but are all compromised solutions.
Numerical simulation is not limited in the same way and permits investigation into the condition. However, cornering introduces significant change to the flowfield and this must be accommodated for in several ways. Boundary conditions are required to be adapted to allow for the curved flow occurring within a non-inertial reference frame. In addition, drag begins to act in a curved path and variation in Re occurs within the domain. Results highlight the importance of using correct analysis techniques when evaluating aerodynamic performance for cornering vehicles.