Parachute design is challenging to achieve innovative progress if the dominant role of testing continues, as it will be an increasingly expensive and time-consuming work. The aim of this study is to establish a reliable and efficient design tool using existing advanced numerical modeling methods. This paper presents a numerical method based on two-way coupled fluid-structure interaction (FSI) strategies for predicting aerodynamic and flight performance for parafoil design optimization. The nonlinear finite element method was used for the canopy fabric model and flow field, and the fluid dynamics were solved by Reynolds-averaged Navier-Stokes with the Spalart-Allmaras turbulence model. The FSI simulations are performed to assess the aerodynamic performance and structural deformations of full-scale parafoil canopies. The equilibrium shape of the parafoil canopy under steady gliding states and the relevant flow field were analyzed to enhance confidence and understanding in the performance prediction of new parachutes. Three-dimensional FSI simulation results of parafoils show that the inflation caused flexible bulges of canopy cells, and the maximum lift coefficient increased more than 16% with a higher stall angle of attack than that of the rigid body model. A parafoil with a smaller leading edge inlet or a scaling down area can improve the aerodynamic performance, mainly manifested in a higher lift-to-drag ratio and better anti-stall performance. Finally, the prediction results of parafoil glide performance were verified by flight test data, and the prediction accuracy of the flexible model is more than 10% higher than that of the rigid model. This work makes the simulation tools a step closer to practical application.

如果测试的主导作用继续存在，降落伞设计将难以实现创新进步，因为这将是一项越来越昂贵和耗时的工作。本研究的目的是使用现有的先进数值建模方法建立可靠且高效的设计工具。本文提出了一种基于双向耦合流固耦合 (FSI) 策略的数值方法，用于预测翼伞设计优化的空气动力学和飞行性能。冠层结构模型和流场采用非线性有限元法，流体动力学采用雷诺平均纳维-斯托克斯和 Spalart-Allmaras 湍流模型求解。FSI 模拟用于评估全尺寸翼伞舱盖的空气动力学性能和结构变形。分析了稳定滑翔状态下翼伞冠层的平衡形状和相关流场，以增强对新型降落伞性能预测的信心和理解。翼伞的三维FSI模拟结果表明，膨胀导致冠层细胞柔性凸起，最大升力系数增加16%以上，失速迎角高于刚体模型。翼翼前缘进气口较小或按比例缩小面积可以提高气动性能，主要表现在更高的升阻比和更好的抗失速性能。最后通过试飞数据验证了翼伞滑翔性能的预测结果，柔性模型的预测精度比刚性模型提高了10%以上。