一种新型可控方向的再入充气罩

A new controllable inflatable shield for reentry

充气式再入与降落技术(IRDT——Inflatable Reentry and Descent Technology)是近年来出现的一种新型的航天回收技术。它的结构简单、回收成本低,极大地改善了返回式飞行器的气动加热环境,同时降低了飞行器表面的热流密度。本文在现有技术的基础上提出了一种可控方向的再入充气罩,研究表明将其应用于返回式飞行器的回收时,可在低密度大气层内将飞行器的速度降至较低水平(20m/s以内),从而降低了对防热材料的要求。另外,在没有附加动力装置的情况下可通过对充气罩气囊的充/放气来主动控制返回式飞行器的姿态,从而控制着陆点的方位。数值模拟结果表明该再入充气罩可为返回式飞行器提供足够的阻力和偏转力矩,从而起到减速和控制的作用。气动热分析结果表明:该再入充气罩在返回过程中的气动加热情况(最大热流密度为426kW/m2)远小于传统返回舱(最大热流密度为4826kW/m2),从而大幅度地降低了防热系统设计的复杂度。

IRDT（Inflatable Reentry and Descent Technology）,which is characterized by simple structure and low recovery cost,is a new concept for spacecraft reentry in recent years.It can improve the aerodynamic heating environment so the requirement for the shield material can be reduced greatly.By considering all of above factors,a new controllable inflatable shield for reentry is presented.On one hand,this shield can decelerate the reentry flight vehicle to a very low velocity（lower than 20m/s） in low density atmosphere,and thus alleviate the aerodynamic heating to the material of the shield immensely.On the other hand,the shield improves the accuracy of the landing point for the reentry flight vehicle because it can actively adjust the attitude of the reentry flight vehicle according to its predesigned trajectory by inflating or deflating its inflatable bags without any thrusters.Results of CFD simulation show that this kind of inflatable shield for reentry can provide adequate aerodynamic forces and moments for deceleration and attitude control.Analysis of aerodynamic heating reveals that the complexity for shield designing can be heavily reduced,because the heating rate to shield surface（peak heat flux 426kW/m 2） is lessened largely compared to traditional process of reentry without this shield（peak heat flux 4826kW/m 2）.