Computational analysis of vortex dynamics and aerodynamic performance in flying-snake-like gliding flight with horizontal undulation
Computational analysis of vortex dynamics and aerodynamic performance in flying-snake-like gliding flight with horizontal undulation
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DOI：
10.1063/5.0125546
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发表时间：
2022-12-01
影响因子：
4.6
通讯作者：
Dong, Haibo
中科院分区：
文献类型：
--
作者：
Gong, Yuchen;Wang, Junshi;Dong, Haibo
本文根据飞蛇滑翔过程的运动学，对蛇形模型空中起伏的流动动力学进行了数值研究。该模型在水平面内周期性地施加空中波动，在水平面内分配攻角（AOA）范围以模拟真实的滑翔运动。使用基于浸没边界法的不可压缩流求解器来模拟流动。局部网格加密网格块的实现，以确保网格分辨率周围的运动物体。结果表明，起伏体在迎角45 °时产生最大升力。涡动力学分析揭示了一系列涡结构，包括机身周围的前缘涡、后缘涡和叶尖涡。其他关键参数，包括波动频率和雷诺数的变化也被发现影响所研究的蛇形模型的空气动力学，其中波动频率的增加增强涡的稳定性和雷诺数的增加增强升力生产由于加强LEV。这项研究代表了第一次研究的空气动力学的整个身体的蛇，以及它的波动运动，提供了一个新的基础，研究细长的柔性飞行器的力学。
This paper numerically studies the flow dynamics of aerial undulation of a snake-like model, which is adapted from the kinematics of the flying snake (Chrysopelea) undergoing a gliding process. The model applies aerial undulation periodically in a horizontal plane where a range of angle of attack (AOA) is assigned to model the real gliding motion. The flow is simulated using an immersed-boundary-method-based incompressible flow solver. Local mesh refinement mesh blocks are implemented to ensure the grid resolutions around the moving body. Results show that the undulating body produces the maximum lift at 45 degrees of AOA. Vortex dynamics analysis has revealed a series of vortex structures including leading-edge vortices (LEV), trailing-edge vortices, and tip vortices around the body. Changes in other key parameters including the undulation frequency and Reynolds number are also found to affect the aerodynamics of the studied snake-like model, where increasing of undulation frequency enhances vortex steadiness and increasing of Reynolds number enhances lift production due to the strengthened LEVs. This study represents the first study of both the aerodynamics of the whole body of the snake as well as its undulatory motion, providing a new basis for investigating the mechanics of elongated flexible flyers.