Numerical and experimental investigation of the steering performance of a ringsail parachute

环帆伞可操纵特性仿真与试验研究

¹ College of Astronautics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
² Beijing Institute of Space Mechanics & Electricity Beijing 100094, China
³ Laboratory of Aerospace Entry, Descent and Landing Technology, CASC, Beijing 100094, China

Received: 7 October 2023

Abstract

In order to investigate the steering performance of the ringsail parachute, the effect of two different steering approaches on the aerodynamic and gliding characteristics of a ringsail parachute is analyzed by using the numerical simulation and wind tunnel test. The first steering approach is to make ringsail parachute drift off course by changing the length of the suspension lines, while the second one is to make ringsail parachute close up by changing the length of the reefing control lines. Numerical simulation is performed using the arbitrary Lagrangian-Eulerian fluid-structure interaction method, and the corresponding wind tunnel test is conducted to compare with the results of numerical simulation. The results show that the first steering approach can effectively change the drag coefficient of the ringsail parachute, i.e., the drag coefficient is greatly reduced as the length of the suspension lines is shortened, and in the meanwhile, compared with the non-steering ringsail parachute, the improvement of the gliding ratio can be up to 80%, which demonstrates the benefits for the gliding ability; While the second steering approach has an significant impact on the drag characteristics of the ringsail parachute, i.e., as the length of reefing control lines is shortened, the reefing effect is enhanced and the drag characteristics is reduced, whereas compared with the non-steering ringsail parachute, the improvement of the gliding ratio only reaches up to 10%, which demonstrates that the reefing control has little effect on the gliding performance. Comparison between the results obtained by the wind tunnel test and numerical simulation shows that the trend of drag coefficient and drag characteristic curves are basically consistent, and the relative error between them is within 20%, indicating the reliability of the numerical method.

摘要

为了研究环帆伞的可操纵特性, 采用数值仿真与风洞试验相结合的手段分析了2种不同的操纵方式对环帆伞气动和滑翔性能的影响。第一种操纵方式为通过改变其中1组伞绳长度对环帆伞进行拉偏操作, 第二种操纵方式为改变控制伞绳的长度使环帆伞呈收口状。数值仿真采用ALE(arbitrary Lagrangian-Eulerian)流固耦合方法, 并进行了相应的风洞试验。结果表明: 拉偏操作能够有效地改变环帆伞的阻力系数, 且在一定长度范围内, 随着拉偏伞绳长度缩短, 阻力系数明显减小, 同时相较于未经过操纵操作的环帆伞, 滑翔比最大提升幅度可达80%以上, 具备一定的滑翔能力; 收口操作对环帆伞的阻力特征影响较为显著, 且控制伞绳长度越小, 收口幅度越大, 阻力特征越小, 但相较于未经过操纵操作的环帆伞, 滑翔比最大提升幅度仅为10%左右。风洞试验和数值仿真结果的对比显示, 阻力系数和阻力特征曲线的变化趋势基本一致, 且两者的相对误差在20%以内, 验证了仿真方法的可靠性。