A Kinetic-Model Analysis of the Source Expansion Flow into Vacuum

概要

論文の詳細を見る
The source expansion flow into vacuum is analysed on the basis of the complete third-order hierarchy kinetic model, which resembles the Boltzmann equation correctly up to the lower 20 moments regarding the collisional integral. The numerical procedure is deviced so as to be able to take into account the distribution associated with the inverse radial velocity. The solution thus obtained indicates smooth transition from the equilibrium at the sonic point to the non-equilibrium far downstream. Comparison is made with the moment method as well as the simple Krook model. As for the distributions of the temperature and number density, the moment method indicates appreciable deviation from the hierarchy model for greater Knudsen numbers, while the Krook model is in good agreement with the hierarchy model over a wide range of Knudsen numbers. The latter implies that the higher-order moments as the heat flux play no significant role on the behavior of temperature freezing.
宇宙航空研究開発機構の論文