Numerical investigations of the flow around rotating wheels with the purpose of tracing tyre dust

Abstract

As we move into an era of electrification of vehicles, there is a constant need to suppress the environmental impact caused by these vehicles. Electric vehicles have drastically lowered exhaust gas emissions but on the flip-side, it has significantly increased non-exhaust emissions. With more than 1 billion passenger vehicles roaming the streets today, it is evident that non-exhaust emissions will only rise in the upcoming years as more BEVs are churned out by manufacturers. Non-exhaust emissions majorly constitutes of tyre wear and brake wear. Several experiments have shown the particulate matter that is abraded off the tyres is charged and hence can be trapped using static electricity. In this work, the complex flow around rotating wheels and inside the wheelhouse is investigated. The work also extends into investigating the effectiveness of a device obtained from The Tyre Collective, which captures these particulate emissions. Using numerical simulations, a generic model of the AeroSUV is studied along with TTC’s device. It was determined that the device placement is not ideal and, having an externally mounted device is prone to vibrations and contamination due to soiling. The change in overall drag and rear wake profile is shown with the help of a comparison study of the vehicle with and without the device. The shape of the device has been shown to restrict flow behind the rear wheels to some extent. Additionally, flow recirculation at the inlet of the device is shown using streamline tracers. The study also shows that the majority of the mass flow of air through the device comes from the front, through the un derbody. Furthermore, based on the numerical analysis several design recommendations were provided. Lastly, this investigative study has shown that simulating particles using multiphase will be worthwhile in providing more information and, a numerical method for both wheel rotation modelling and particle tracing. Furthermore, upcoming Euro 7 emission norms are speculated to have stringent regulations on tyre and brake wear. Hence, capturing these particulate emissions at the source would be highly beneficial and to do so, a more sophisticated numerical analysis of particle behaviour is necessary to decipher the optimal methods to capture them.