Numerical analysis on effect of back/front windshied and hood angle on automotive aerodynamic drag

The connection between the result of numerical simulation of aerodynamic drag coefficients of hatch-back car and the angle change of back and front windshield and hood was analyzed. In order to find out how the angle change affect the drag coefficient respectively and comprehensively. By using CFD methods to simulate the drag coefficient of the change of back and front windshield angle and hood angle of MIRA body respectively. And then, 3 angles of back and front windshield angle and hood angle were chosen. Totally 27 kinds of cases were simulated to find out combined influence and to confirm orthogonal test can be used in aerodynamic drag optimizations or not. The results show that: the change of front windshield angle and hood angle had nothing to do with back angle in drag coefficient and orthogonal test can be used in aerodynamic drag optimization design.