稀薄大气下机械展开式再入飞行器气动特性研究

以机械展开式再入飞行器为研究对象,采用DSMC(直接蒙特卡洛模拟)方法计算分析了其在稀薄大气环境下的气动特性.讨论了飞行器在不同高度下的流场特性和升阻及配平特性,结果表明飞行器流场及受力特性对大气稀薄程度显示出较强的敏感性;进一步分析了连续流过渡至稀薄大气下飞行器的阻力系数,得出了随着来流Knudsen数增加,大气稀薄效应逐渐显现,传统的CFD方法已不再适用于描述流动特征的结论,同时给出了依据来流Knudsen数大小采取CFD和DSMC方法分别进行计算分析的建议.

Study on Aerodynamic Characteristic of Mechanical Deployable Reentry Vehicle in Rarefied Flow

Setting mechanical deployable reentry vehicle as study object ,the aerodynamic characteristic of the vehicle in rarefied environment is calculated and analyzed with DSMC ( Direct Simulation Monte Carlo) method.The flow field under different altitude is discussed ,as well as lift-to-drag and trim prop-erties,which demonstrate the sensitivity of the flow field and aeroforce properties to the degree of airflow rarefied.Furthermore,drag coefficients of the vehicle range from continuum flow to rarefied regime are discussed ,which indicates that rarefied effect become progressively obvious as the airflow Knudsen num -ber grows and traditional CFD method is unable to clarify the flow properties in this condition .At the same time,suggestion about adopting CFD and DSMC method separately according to the airflow Knudsen number in the computation is made.