Abstract
Optimizing the aerodynamic parameters of road vehicles is essential due to their impact on the environment. It is a special aim of developments, including electric and non-electric vehicles. A lot of research is being conducted according to energy efficiency and range. These parts are the most significant directions of development. Aerodynamic parameters such as drag coefficient exert a significant influence on vehicle energy efficiency. The purpose of this paper is to investigate the aerodynamic parameters of the Ahmed body in rainy weather conditions. Different types of rain and vehicle speeds are studied and compared to each other to examine their effect on the drag coefficient. The examination is carried out using the Computational Fluid Dynamics (CFD) method. In the two-phase simulations, the rain is modeled as solid particles. Results can be used to obtain the most fuel- or electricity-efficient rain type-vehicle speed combinations and thereby can help to contribute a more sustainable transport. The results clearly show that rain has a measurable effect on the drag coefficient. As the rain intensity increases, the drag coefficient increases, too. However, there are uncertainties in the upward trend. As airspeed increases, the increasing trend becomes more stable.
