环帆伞解除收口充气展开过程数值模拟及应用

Inflatable Simulation Research and Application of Reefed Ringsail Parachute

针对目前大多数降落伞充气展开过程仿真中时间零点和初始进气口大小的设置与实际使用状态不一致,以及由此导致的充气时间、开伞载荷、充气过程中的投影面积和体积变化规律等仿真结果利用受限和验证的充分性不足等问题,文章通过在降落伞仿真模型中增设收口绳结构,使用单元失效的控制方式,对环帆伞收口稳定状态和解除收口后的充气展开过程进行了数值模拟研究。经过与空投试验相关结果的对比验证,表明降落伞收口控制方法和解除收口后的充气展开过程仿真方法是可行的。同时利用充气过程中的伞衣投影面积及体积变化规律等仿真结果处理得到了伞衣阻力面积和附加质量变化规律,引入量纲为1的充气时间对其进行了处理。最后结合物伞系统动力学模型,实现了物伞系统试验中的开伞载荷预测分析,结果与试验数据吻合得较好。研究成果为降落伞充气性能分析提供了一种具有较高精度的开伞载荷预测方法。

Currently,many parachute simulation models use inconsistent settings for parachute inflation zero time and initial air inlet size,which limits the usefulness of simulation results such as inflation time,opening load,canopy projected area and volume change during the inflation process.This also causes simulation verification insufficient.To address this issue,this paper introduces a reefing line with unit failure control method into a ringsail simulation model,and conducts a numerical simulation study on stable state of the ringsail and inflation process after the reefing line failed.Then comparison and verification with the results of airdrop test indicate that the reefing line control method and the inflatable simulation after the reefing line failed are feasible.Meanwhile,canopy projected area and volume curves are processed from the simulation data,and applied to obtain drag area and added mass of the parachute,which are further treated as dimensionless inflation time forms.Finally,combined with the forebody-parachute system dynamics model,the prediction and analysis of the ringsail opening load are realized,and the results agree well with airdrop test results.The research achievements also provide a high-precision method about predicting the opening load for parachute inflation performance analysis.