在地球大气层与火星大气层中,使用自己编制的DSMC(direct si mulation Monte Carlo)源程序完成了四种飞行器(即Apollo,Orion,Mars Pathfinder以及Mars Microprobe)高超声速穿越稀薄气体时的三维绕流计算,给出了上述飞行器42个典型飞行工...在地球大气层与火星大气层中,使用自己编制的DSMC(direct si mulation Monte Carlo)源程序完成了四种飞行器(即Apollo,Orion,Mars Pathfinder以及Mars Microprobe)高超声速穿越稀薄气体时的三维绕流计算,给出了上述飞行器42个典型飞行工况(其中包括在地球大气层中,飞行高度从250 km变到90km,飞行攻角从45°变到-45°,Knudsen数从111.0变到0.0057,飞行速度从7.6km/s变到9.6km/s;在火星大气层中,飞行高度从141.8km变到80.28km,飞行攻角从45°变到0°,Knudsen数从100.0变到0.0546,飞行速度从7.47km/s变到6.908km/s)时详细气动力与气动热的数值结果,并与国外的飞行数据以及美国NASA(National Aeronautics and Space Administration)Langley研究中心发表的计算结果进行了比较,所得结果令人满意.文中采用了三种无量纲参数分别刻画这四种典型飞行器绕流流动的热力学非平衡、化学反应非平衡以及壁面热流分布的特征,这些结果对于指导空间飞行器的热防护气动设计十分有益.展开更多
By using the non-equilibrium thermodynamic approach,the possibility of the existence of a steady state for non-equilibrium adsorption with a temperature difference between body gas and adsorbed gas was confirmed and t...By using the non-equilibrium thermodynamic approach,the possibility of the existence of a steady state for non-equilibrium adsorption with a temperature difference between body gas and adsorbed gas was confirmed and the steady state was determined.The chemical potential difference between body gas and adsorbed gas was obtained and equations for evaluating the adsorption entropy and the isosteric heat of adsorption were derived.The changes of the adsorption entropy and the isosteric heat of adsorption at the non-equilibrium steady state relative to those at the equilibrium state were calculated and the results were compared with those obtained using the traditional equilibrium thermodynamic method.The comparison suggests that the changes of the adsorption entropy and the isosteric heat of adsorption obtained using the non-equilibrium thermodynamic approach are related with not only temperature but also adsorptive state,while those obtained using the equilibrium thermodynamic method are only a function of temperature.The main reason is that the present study treats the adsorption and gas temperature change as an integrated process and considers their interaction,whereas the equilibrium thermodynamic approach separates the adsorption and gas temperature change as two independent processes and neglects their interaction.展开更多
文摘在地球大气层与火星大气层中,使用自己编制的DSMC(direct si mulation Monte Carlo)源程序完成了四种飞行器(即Apollo,Orion,Mars Pathfinder以及Mars Microprobe)高超声速穿越稀薄气体时的三维绕流计算,给出了上述飞行器42个典型飞行工况(其中包括在地球大气层中,飞行高度从250 km变到90km,飞行攻角从45°变到-45°,Knudsen数从111.0变到0.0057,飞行速度从7.6km/s变到9.6km/s;在火星大气层中,飞行高度从141.8km变到80.28km,飞行攻角从45°变到0°,Knudsen数从100.0变到0.0546,飞行速度从7.47km/s变到6.908km/s)时详细气动力与气动热的数值结果,并与国外的飞行数据以及美国NASA(National Aeronautics and Space Administration)Langley研究中心发表的计算结果进行了比较,所得结果令人满意.文中采用了三种无量纲参数分别刻画这四种典型飞行器绕流流动的热力学非平衡、化学反应非平衡以及壁面热流分布的特征,这些结果对于指导空间飞行器的热防护气动设计十分有益.
基金supported by the National Natural Science Foundation of China (50576040)
文摘By using the non-equilibrium thermodynamic approach,the possibility of the existence of a steady state for non-equilibrium adsorption with a temperature difference between body gas and adsorbed gas was confirmed and the steady state was determined.The chemical potential difference between body gas and adsorbed gas was obtained and equations for evaluating the adsorption entropy and the isosteric heat of adsorption were derived.The changes of the adsorption entropy and the isosteric heat of adsorption at the non-equilibrium steady state relative to those at the equilibrium state were calculated and the results were compared with those obtained using the traditional equilibrium thermodynamic method.The comparison suggests that the changes of the adsorption entropy and the isosteric heat of adsorption obtained using the non-equilibrium thermodynamic approach are related with not only temperature but also adsorptive state,while those obtained using the equilibrium thermodynamic method are only a function of temperature.The main reason is that the present study treats the adsorption and gas temperature change as an integrated process and considers their interaction,whereas the equilibrium thermodynamic approach separates the adsorption and gas temperature change as two independent processes and neglects their interaction.
