Abstract: Regolith thermal energy reservoir is an important way of insitu resource utilization on the moon, and is also a potential method to solve the energy demand of future lunar base construction. A porous medium model of regolith thermal energy reservoir based on spherical stacking was established to simulate the flow and heat transfer process numerically. The shell of the thermal energy reservoir is a fuel tank of descent module, and the helium is used as the working heat transfer medium. Numerical study was carried out to investigate the effects of the stacking mode and diameter of regolith balls on the heat transfer process of the thermal energy reservoir under different flow pressure drop, and the dynamic process of the thermal energy reservoir was analyzed. The results show that the coefficient of heat storage performance (CHSP) of the simple cubes(SC) model is 302% higher than that of the face centered cubes(FCC) model. It is also found that there is an optimal diameter of the regolith ball, which can make the thermal energy reservoir obtain the maximum heat storage under the unit pump power, and the optimal value decreases with the increase of inlet and outlet pressure difference of the fluid. This study can provide theoretical basis and guidance for the design and optimization of regolith thermal energy reservoir. 

Key words: regolith, thermal energy reservoir, porous medium, numerical simulation, spherical stacking, heat transfer characteristics