Numerical simulation of aerodynamic characteristics and heating for grid fin missiles

A grid fin is an unconventional missile control surface comprising an outer frame supporting an inner grid of lifting surfaces. Although the topic of grid fin aerodynamics has been studied by many researchers, only a few have considered aerodynamic heating, generating a high-quality structured grid that remains to be a difficult task. An effective method of grid partition and an aerodynamic prediction method to simulate the viscous flow fields of grid-fin configurations at supersonic Mach numbers have been developed. Multi-block and H-O-type grid treatments are developed for complex grid fin configurations. The viscous flow over a tail-controlled missile with grid fins at a Mach number of 2.5 and several angles of attack is calculated using computational fluid dynamics. Additionally, the heat flux distribution of grid fins is investigated, and the effects of shock wave interaction on heat flux are analyzed. The numerical results show good agreement with the measured data, and confirm that this method is an effective way to numerically simulate viscous grid fin flow fields. Furthermore, the aerodynamic heating results show that, because the peak heat flux on the shock wave interaction region is lower than that on the leading edge of the grid fin, it does not affect the thermal protection of the grid fin.