Effects of Rear Window Angle on Car Aerodynamic Characteristics

The research of automobile aerodynamic performance has become the focus and hotspot of automobile industry. Compared with traditional wind tunnel test research, it has the disadvantages of long period of experiment and high cost, which makes numerical simulation play an increasingly important role in automobile aerodynamics research. The geometric model of a car with different rear window inclination angle is established by 3D modeling software, and the vehicle dynamics is analyzed by CFD technology. The pressure distributions and velocity distributions and aerodynamic characteristics of the results were obtained. The results show that the airflow is separated at the rear end, producing different turbulence zones, which changes the pressure difference between the front and rear of the vehicle, and causes the drag and lift of the vehicle to change. When the rear windshield angle is about 45°, the drag coefficient is the largest and the lift coefficient is the smallest. According to the simulation results, a certain theoretical basis is provided for the optimization of the angle design of the rear windshield of a car, which has certain guiding significance for practical applications.