Heat transfer enhancement in a regenerative cooling channel using porous media

The endothermic hydrocarbon fuels play an important role in the thermal management of hypersonic scramjet. However, there often involve serious thermal stratifications in the regenerative cooling channel. The present work conducts a two-dimensional cooling channel numerical simulation with the addition of porous media using a unique global chemical kinetics model to clarify the increase of the total heat sink of hydrocarbon fuels. It is proposed that the addition of porous media is a coupling process, which not only enhances heat transfer, but also will bring resistance to heat. Therefore, the energy source term is included in the numerical simulations, which makes our calculations closer to the actual working condition compared to the previous numerical modeling. The simulated results indicate that compared to the smooth channel, the thermal stratifications are relieved in the cooling channel with the addition of porous media, while the thermal cracking of n-decane is inhibited due to the decrease of the wall temperature. In addition, with the decrease of porosity of porous media, the total heat sink of fuel increases. The heat transfer coupling rule of porous media is studied by placing porous media at different positions, and the optimal placement position is found.