The cubic pitching moment coefficient of spin-stabilized projectiles

Abstract

This technical note presents a feasible method to effectively predict the cubic pitching moment coefficient for spin-stabilized projectiles. First, a surrogate model for predicting the cubic moment coefficient is constructed by using the Kriging method to relevant published data of several typical spin-stabilized projectiles. The result of a wind tunnel test validates the accuracy of the Kriging prediction, implying that this prediction model complements the current research literature. Second, the global sensitivity analysis combined with this prediction model is used to assess the effect of the shape parameters of spin-stabilized projectiles on the cubic pitching moment coefficient. As a result, the relationship between the shape parameters and the nonlinear pitching moment coefficient is preliminarily explored. The results of an example show that the cylindrical part length, the head shape parameter and the nose length have greater influence, whereas the boat-tail length has the weakest influence.