DSMC Simulation of Gas Heat Transfer Between Coaxial Cylinders

How to reduce the heat loss caused by heat conduction of gas between coaxial cylinders is of vital importance. The problem is widely presented in the oil transportation pipeline and the solar parabolic trough receiver, where hydrogen percolation is inevitable. One of the most common methods is to fill with inert gas, such as argon and xenon. In this work, several factors affecting the heat loss in the coaxial cylinders are studied using the DSMC method, including the wall thermal accommodation coefficient, wall temperature, gas composition, and number density of the gas mixture. After determining argon as the filling gas, the effect of different combinations of the argon and hydrogen densities on the heat flux was studied, and an empirical formula was proposed to evaluate the heat flux of the Ar-H-2 mixture.