Abstract: To study the experimental correlativity of aerodynamic characteristics of intake and vent grilles in armored vehicles, the aerodynamic performance experiments of grille were carried out based on some typical structures. The aerodynamic and protective performances of air intake and vent grilles in China and U.S. military armored vehicles were comparatively analyzed. The results show that the protective performance of intake and vent grilles in U.S. military armored vehicles is better, but their aerodynamic performance is lower. The aim of grille design is to get the maximum protective capability with minimum throttling pressure loss and enough cooling air mass flux. The grille opening coefficient as a dimensionless parameter was proposed to evaluate the grille leaf structure. It is shown from analysis that the smaller opening coefficient means the stronger protective capability on the basis of certain grille material and leaf thickness.

Key words: fluid mechanics, grille, testing study, opening coefficient, protective performance