凹腔尺寸对迎风凹腔与逆向喷流组合热防护系统性能的影响

Effect of cavity physical dimension on forward-facing cavity and opposing jet thermal protection system cooling efficiency

针对高超声速飞行器热防护系统(TPS)的设计,对迎风凹腔与逆向喷流组合热防护系统展开研究.在数值方法实验验证的基础上,通过求解Navier-Stokes方程得到了带组合热防护系统的鼻锥的流场结构以及壁面热流分布.验证了组合热防护系统的有效性.在逆向喷流条件不变的情况下,进一步研究了凹腔的尺寸变化对其防热能力的影响.研究发现:凹腔的直径越小,深度越深,气动加热值越低.自由来流与逆向喷流形成的回流区在减少鼻锥的气动加热上起到关键的作用.相对于凹腔深度的变化,鼻锥壁面的气动加热更敏感于凹腔直径的变化.

Design of the thermal protection system（TPS） with the forward-facing cavity and opposing jet combined configuration was investigated numerically for the hypersonic vehicle.The numerical method was validated with the related experiments.The flow field parameters and surface heat flux distribution were obtained by solving the Navier-Stokes（N-S） equations.The validity of the combined TPS was testified and the effect of the cavity physical dimension on cooling efficiency of the combined TPS was discussed.The results show that the TPS with smaller diameter cavity has smaller aerodynamic heating and the TPS with larger length cavity has higher heat flux reduction.The recirculation region plays a pivotal role for the reduction of heat flux.The aerodynamic heating is more sensitive to the changing of the cavity diameter than the cavity length.