DSMC算法气体壁面相互作用模型

研究了二维非结构网格高超声速稀薄流DSMC方法中气体与壁面相互作用的数值模型。发展了一种基于辐射平衡的壁面温度边界条件，与恒温壁面边界条件相比，该温度边界条件可以克服恒温壁面边界条件的自身缺陷并且能够在流场模拟中适时给出更贴近真实情况的壁面温度；采用了由完全漫反射和纯镜面反射模型组合而成的Maxwell壁面反射模型，该壁面反射模型能够更好地描述气体模拟分子在壁面散射的真实情况。采用本文方法对钝头体外形进行了数值模拟，结果表明本文采用的气体壁面相互作用模型能够提高钝头体背风面后部流场对温度变化的敏感度，并且随着飞行高度提升，敏感度有减弱的趋势。

Gas-Surface Interaction Models for DSMC Method

Gas-surface interaction models in direct simulation Monte Carlo (DSMC) method for hypersonic rarefied flow is studied based on unstructured grids. A wall boundary condition based on radiative equilibrium is developed, which can overcome the defects of isothermal boundary condition and provide more precise wall temperature distribution during numercial simulations. The Maxwell reflection boundary model, coupled with diffuse reflection and specular reflection,is applied. Numerical results of a blunt body configuration are obtained. Test cases show that the developed models can improve the sensitivity of the temperature variation in afterbody field, and the sensitivity decreases with the simulated flying altitude increases.