SAE International Numerical Investigation of Features Affecting Rear and Side Body Soiling 2017-01-1543

Vehicle rear and side body soiling has been a concern since the earliest cars. Traditionally, soiling has been seen to be less importance than vehicle aerodynamics and acoustics. However, increased reliance on sensors and cameras to assist the driver means that there are more surfaces of the vehicle that must be kept clean. Failure to take this into consideration means risking low customer satisfaction with new features. This is because they are likely to fail under normal operating conditions and require constant cleaning. This paper numerically investigates features known to have an influence on side and rear face soiling with a demonstration vehicle. These changes include rim design, diffuser strakes and diffuser sharpening. While an exhaustive investigation of these features is beyond the scope of this study, examples of each feature will be considered. This will include discussion on what flow changes were being attempted with a given feature and how this was expected to influence the soiling performance. Numerical simulation will then be used to evaluate the impact of a given feature and discern if the desired impact was achieved.