Numerical study on transient response of transpiration cooling with hydrocarbon fuel as coolant

A transient non-thermal equilibrium model was established to solve the transient process of transpiration cooling, which considers the influence of cracking reaction. The occurrence of cracking reaction leads to the increase of inlet pressure, thermal diffusion coefficient and heat transfer coefficient and effectively reduces the temperature of porous matrix. In the absence of external oscillation excitation, the change rate of porous matrix temperature and fluid temperature with heating time gradually decreases. In the case of unsteady heat flux, the oscillation amplitude of fluid parameters near the outlet of porous media is larger. The increase of thermal conductivity of solid matrix can effectively restrain the temperature oscillation caused by external heat flux, but the amplitude of coolant supply pressure increases with the increase of thermal conductivity, which is not conducive to the supply of coolant. The amplitude of reaction heat is the smallest when the frequency of coolant mass flux and heat flux is the same. The greater inlet pressure oscillation is formed when the coolant supply cycle period is lower than the cycle period of heat flux.