基于DSMC方法的超低轨道卫星阻力特性分析

Analysis on drag characteristics of ultra-low orbit satellite based on DSMC method

为向工程中卫星结构设计提供载荷依据,基于直接模拟蒙特卡洛仿真方法,采用Maxwell漫反射和镜面反射联合模型,对一典型超低轨道卫星的阻力特性进行研究.分析了结构网格密度、卫星头锥、星体长细比等参数对阻力特性的影响,并通过算例与文献结果对比以验证方法的准确性.结果表明,卫星阻力主要由迎风面投影面的压差阻力和卫星侧面的切向摩擦阻力组成.针对268 km典型超低轨道卫星模型,相同迎风面投影面积下,较尖的头锥结构能略微降低平飞阻力.卫星星体的长细比每增加1,阻力提升约5%~8%.全动尾翼通过改变攻角可以获得升力,升阻比为0.10~0.34.

To provide convincing loads for satellite structural design in engineering,the drag characteristics of a typical ultra-low orbit satellite was studied based on the direct simulation Monte Carlo(DSMC)method by using the model combining Maxwell's diffusion and specular reflection.The effects of the structural mesh density,the satellite nose cone,the slenderness ratio on the drag characteristics were analyzed.The accuracy was verified by comparing the simulation results with the literature results.The results show that the satellite drag is mainly composed of the pressure-difference drag on the inflow projective surface and the tangential frictional drag on the side surfaces of the satellite.For the typical ultra-low orbit satellite studied at the altitude of 268 km,pointed nose cone structures can slightly reduce the drag in flight with the same projective surface area.The drag increases by about 5%to 8%with the slenderness ratio increasing by 1.Changing the angle of attack of all-moving tails can generate the lift force with the lift-drag ratio of 0.10 to 0.34.