Numerical simulation study of transpiration cooling with hydrocarbon fuel as coolant

Transpiration cooling is an advanced active thermal protection technology, which has been studied widely. The effects of cracking reaction on transpiration cooling are considered in this paper when n-decane is used as coolant. The porous wall temperature is reduced and the cooling efficiency is improved due to the cracking reaction. The cracking of n-decane produces a large number of small molecular products, and the random motion of the small molecular products increases the turbulent kinetic energy near the wall. The synergistic effect of the flow field and the total enthalpy near the porous wall is analyzed. The energy fluctuation caused by the cracking reaction is not enough to change the momentum distribution at the porous wall. The pressure increase caused by the small molecular gas generated by the cracking of n-decane can block the flow inside the porous media. The cooling effect brought by the cracking reaction is more obvious when increasing the coolant inlet temperature and the mainstream temperature.