Improvements in NASCAR Race Vehicle Side Force and Yawing Moment Stability in Race Conditions Using Active or Passive Blowing

摘要

Aerodynamic yawing moment and front and rear side force are important performance characteristics to NASCAR race vehicles on oval tracks. Computational Fluid Dynamics (CFD) was used to study the cause of side force and yawing moment variation between a leading and trailing car when in proximity to each other. Implementation of rear side force reducing design features such as removing body asymmetry and reducing rear quarter panel size showed marginal improvement in yawing moment variation. The use of front and rear blowing at each corner of the car was able to induce both positive and negative change in the overall yawing moment of an isolated car via change in front and rear side force. Application of the optimal blowing strategy for each vehicle was shown to reduce the absolute mean yawing moment variation by up to 53% for selected multi-vehicle configurations that displayed high yawing moment variability in the baseline condition.