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昆虫在自然界中飞行时多会受到侧风的干扰,因此了解侧风作用下昆虫拍动翅上气动力的变化对昆虫飞行机理的研究工作具有重要意义。应用计算流体力学(CFD)方法模拟了存在侧风时拍动翅上绕流,并与正常悬停情况进行对比,从侧风的方向和强度2个方面考察了其对拍动翅气动特性的影响。结果表明:侧风对拍动翅气动特性的改变包含2个流动机制的贡献,即相对速度效应和前缘涡轴向速度效应,且从翅尖吹向翅根的侧风与从翅根吹向翅尖的侧风对气动力的影响有着显著的不同;而不同强度的同向侧风下,气动力的改变类似,仅存在数值上的差异。
Insects fly in nature when they will be more affected by the crosswind, so understanding the wind under the action of insects flapping aerodynamic changes on the flight mechanism of insect research is of great significance. The computational fluid dynamics (CFD) method was used to simulate the flow around flapping wings in the presence of crosswind and compared with the normal hovering conditions. The aerodynamic characteristics of flapping wings were investigated from the aspects of the direction and intensity of crosswinds influences. The results show that the change of the aerodynamic characteristics of flapping wings by crosswinds includes the contribution of two flow mechanisms, namely the relative velocity effect and the axial velocity effect of leading edge vortex, The effects of crosswinds on wing tips on aerodynamic forces are significantly different. However, under the same direction of crosswind with different intensities, the changes of aerodynamic forces are similar, and there are only numerical differences.