收放伞绳对十字型伞静态气动特性影响的数值模拟研究

Numerical of Effect of Suspension Line Length of Retraction of the Cruciform Parachute on the Static Aerodynamic Performance

为研究十字型降落伞作为主动控制装置时,其可控性与气动特性的规律,建立了不同伞绳收缩比δ为0、10.0%、12.5%、15.0%、20.0%、25.0%时十字型伞无限质量充气的有限元模型,基于任意拉格朗日-欧拉方法进行数值模拟,分析了十字型降落伞收缩伞绳,引起伞面几何构型不对称对气动特性的影响.结果表明:不同攻角为0°、5°、10°时,十字型降落伞的平均阻力系数随伞绳收缩比δ的增大而减小;十字型伞的瞬时升力峰值随着伞绳收缩比δ的增加而增大,方向始终由伞绳收缩一侧指向另一侧,具有较强的时变特性.

In order to study the steerability and aerodynamic characteristics of cross parachute as an active control device,a finite element model of cross parachutes with a different retracting ratioδ(0,10.0%,12.5%,15.0%,20.0%and 25.0%)was established.Numerical simulation based on arbitrary Lagrange-Euler method was made,and the effect of asymmetry of canopy caused by the retraction of the suspension line on aerodynamic performance was analyzed.Results are as follows.The drag coefficient of the cross parachute decreases with the increase of the suspension retraction ratio,with different angles of attack(0°,5°,10°).The mean drag coefficient of cross parachute decrease with the increase of the suspension retraction ratioδ.The peak value of transient lift of the cross parachute increases with the increase of the suspension retraction ratioδ.The direction of the lift force generated by suspension retracting is always changing,which has a strong time-varying characteristic,pointing from the line retraction to the other side of the cross parachute.