Numerical simulations of flow field and film cooling characteristics in hypersonic vehicles

Film cooling, as an effective approach of active heat protection, has found widespread use in cooling hypersonic vehicles. In this paper, a comprehensive investigation of the cooling efficiency considering multiple factors including nozzle height and cool stream speed has been conducted. Numerical simulations have been applied to re-veal that the cooling stream, with excellent wall adhesion performance, can effectively cool down the surface of the hypersonic vehicle. Particularly, by stabilizing other conditions, higher cooling efficiency can be achieved with larger nozzle height and Mach number. Notably, for small nozzle height, the effect of Mach number on the cooling efficiency can be amplified by the nozzle height, while for sufficiently large nozzle height, this effect tends to be stable. Consequently, with a trade-off between minimizing required cooling stream volume and maximizing the cooling efficiency, the optimized nozzle height is estimated to be 4mm in practical scenarios.