Yaw angle effect on the aerodynamic performance of hatchback vehicle fitted with combo-type spoiler

This study investigated the effect of yaw angle on the aerodynamic performance of hatchback vehicle model fitted with a spoiler featuring a configuration combining the wing and strip spoiler designs. To date, majority of the tests performed on spoilers were done in a straight-ahead driving condition. However, the effect of spoiler is most demanded during cornering for stability reason. A RANS-based Computational Fluid Dynamics (CFD) method was used to simulate the flow. Validation of the method was carried out by comparing the numerically obtained results with the experimental data. The findings show that both the drag coefficient, Cd, and lift coefficient, Cl had increased when the vehicle was subjected to higher yaw angle. The wing part of the spoiler did performed in favour of reducing the Cl , but its contribution to the overall Cl was only about 4.28%. The main body parts contributed to the decrease in Cd and Cl are the front and underbody, respectively