Numerical optimization of aerodynamic configuration of a hollow projectile based on the approximation model

As a new type of supersonic ammunition, the hollow projectile has advantages of low drag and high precision etc., and it has wide applications in aircraft and air defense field. In this paper, based on fourth-order polynomial response surface approximation model, combined with the application of UG, ICEM CFD, FLUENT, MATLAB, etc., and simplex method, the aerodynamic configuration of our previously studied 30mm hollow projectile has been numerically optimized for minimum drag coefficient, and the minimum drag coefficient and optimal aerodynamic configuration parameters were obtained for the hollow projectile at angle of attack α=0° and Mach number Ma=3.0. The minimum drag coefficient has good agreement with our previous numerical result. Based on the same optimal object of minimum drag coefficient, the aerodynamic configuration has been optimized at α=0°, 4°, and Ma=2.5~4.0, and the variation ranges of corresponding configuration parameters were obtained. Moreover, by using Kriging approximation model and NSGA-Ⅱ optimization algorithm etc., based on optimal objects of minimum drag coefficient and maximum lift-drag ratio, the aerodynamic configuration of the hollow projectile has been optimized numerically at α=4° and Ma=3.0, and the optimal aerodynamic configuration has been obtained. Compared with the original hollow projectile, the aerodynamic drag force of the optimized one is significantly reduced. It is verified that approximation model can be applied to optimize aerodynamic configuration of a hollow projectile. This study can provide important guidance for relative engineering applications and investigations.