Moving impingement heat transfer in a three-dimensional rarefied hydrogen gas jet based on the direct simulation Monte Carlo method coupled with the finite difference method

Temperature control systems in low-pressure environments are an important component of precision instruments. In this study, a comprehensive model coupling the direct simulation Monte Carlo (DSMC) method with the finite difference method is proposed to investigate the heat transfer due to the impact of a moving rarefied hydrogen jet. The cooling heat flow calculated using the DSMC method and radiant heat flow calculated using the boundary integral method are considered as the boundary conditions of the substrate, and the temperature distribution of the substrate is solved using the finite difference method. The influences of different inlet pressures, jet apertures, and impact distances on the jet heat transfer intensity are analyzed. The results indicate that the average convective heat transfer coefficient of jet impingement is positively correlated with the inlet pressure and jet aperture, whereas it is inversely correlated with the impingement distance. The structural parameters that meet the temperature control requirements in the substrate are determined using the proposed comprehensive model. These results can be used as a guide for the design of high-precision temperature control devices.