Numerical Investigation on Transient Response of Transpiration Cooling with Phase Change

Abstract

Transpiration cooling with phase change is a novel active thermal protection method with higher cooling efficiency. The modified two-phase mixture model and the multi-domain coupling computation are adopted to study its transient response. Different fluctuation periods of coolant mass flux and different thermal conductivities of the porous matrix are discussed, respectively. The simulation results show that there are clear delay and accumulation effect in the transient response, and the coolant injection pressure is much more sensitive than the temperature to the coolant mass flux. Moreover, both temperature and injection pressure have their own extreme values during transient response. Then, the instability on the porous matrix surface is closely related to the location of the coolant phase transition. Using the porous matrix with greater thermal conductivity can not only help to reduce the surface temperature of the structure under steady condition, but also has stronger stability under transient condition. The research of this work is of great guidance and practical importance for the extension of the application of transpiration cooling with phase change in the real environment.