不同攻角下超声速降落伞伞绳的影响研究

Effects of Suspension Lines on the Supersonic Parachute System at Different Angles of Attack

文章基于一种简易"浸入边界技术"与流固耦合方法对超声速来流条件下的三维降落伞系统进行了数值模拟。研究中,降落伞系统包括前体和伞体,两者通过伞绳连接。文章的研究目的是分析不同攻角下降落伞伞绳对于降落伞系统周围复杂非定常流场的影响,以及对降落伞性能表现的影响。结果表明:在较小的前体和伞体距离下,由于攻角的影响,非定常流场结构呈现上下不对称,并且上下伞绳激波形成时间不同步。随着攻角的增加,上下面的伞绳激波形成时间出现推迟,并且有变弱的趋势。另外,由于攻角与伞绳的综合影响,伞内表面的时间平均压力分布在5o攻角时最小,而在10o攻角时最大,阻力系数却随着攻角的增加而增加。

In the present study,a three-dimensional parachute system in supersonic flow is numerically simulated using a simple ＂immersed boundary technique＂ together with the fluid-structure coupling scheme.The parachute system employed here consists of a capsule and a canopy,where the suspension lines are applied to connect them.The objective of this study is to investigate the effects of suspension lines on the complex unsteady flow structures around the parachute system,and the performance of the supersonic parachute at different angles of attack.As a result,since the distance between the capsule and canopy is rather small,the aerodynamic interactions around the parachute system exhibit more apparent asymmetric flow/shock features when the angle of attack increases,and the suspension line shocks on the upper/lower surfaces are formed at different time.As the angle of attack is increased,the suspension line shocks are postponed to form,and become weaker.In addition,because of the coupling effects of the angle of attack and suspension line shocks,the time-averaged pressure distribution on the canopy inner surface becomes smallest at 5 degree of angle of attack,and reaches to be greatest at 10 degree; however,the drag coefficient increases with the angle of attack increment.