串列式倾斜拍动翼-固定翼构型的升推性能转化研究  

Trade-off of lifting and propulsion capacity of tandem flappingfixed airfoils by inclining the stroke plane

作　　者：李港 吴江浩 李家茗 张艳来 陈隆 Gang Li;Janghao Wu;jaming Li;Yanlai Zhang;Long Chen(School of Transportation Science and Engineering,Beihang University,Bejing 100191,China;Shenyuan Honors College,Beihang University,Bejing 100191,China;School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]不详

出　　处：《Acta Mechanica Sinica》2024年第5期50-60,共11页力学学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.12072013);the China Postdoctoral Science Foundation(Grant Nos.BX20220368,and 2022M720356);Beijing Municipal Natural Science Foundation(Grant No.20L00003).

摘　　要：昆虫和微型飞行器存在间隙狭窄的串列式拍动翼-固定翼构型.与独立的拍动翼相比,两翼之间的干扰作用可以增强推力,但推力增量能否通过倾斜拍动平面而转化为升力尚不清楚.本文采用浸润边界法和格子玻尔兹曼方法研究了这种串列双翼构型在不同拍动平面倾角下的气动性能。结果表明,当拍动平面倾角为75°时,干扰作用产生的大部分推力增量转化为升力增量,证明了通过倾斜拍动平面实现升推转化的可行性。除了几何投影和有效迎角改变的贡献外,升力增量还来自于两翼位置最接近时的额外升力峰,其流动机制包括两部分:一方面,固定翼阻碍了拍动翼产生的射流并在间隙内产生了较强的水平回流,从而增强了拍动翼上翼面后缘附近的低压区;另一方面,固定翼前方的上洗气流增强了拍动翼下翼面的高压区.进一步分析表明,这种增升机制在多个拍动幅度下有效,因此可以认为该机制在三维构型中仍然存在。上述研究结果揭示了一种通过倾斜拍动平面来增强串列式拍动翼-固定翼构型升力的新机制,为以这种构型为基础的微型飞行器提供了新设计方案.A tandem flapping-fixed airfoil configuration with a narrow gap can be found in insects and micro air vehicles(MAVs).Compared to a single flapping airfoil,the interaction between the two airfoils can bring about a thrust enhancement,whereas it is not sure whether this thrust enhancement can be transformed into an improved lifting capacity via some trade-offs.In this paper,the idea of inclining the stroke plane is adopted,and the aerodynamic performance of this tandem configuration at different stroke plane angles is investigated numerically using the lattice Boltzmann method.Results show that most of the extra thrust is converted into the lift increment at the 75o stroke plane,which proves the feasibility of a trade-off between lifting and propulsion capacity.In addition to the contributions of geometric projection and effective incoming flow,the lift increment also originates from an extra transient lift peak when the flapping airfoil and the fixed airfoil are near their closest locations.This lift peak is attributed to the enlarged low-pressure and high-pressure regions at the rear end of the upper and lower surfaces of the flapping airfoil,the underlying flow physics of which is the formation of a reversed horizontal flow and an upwash between two airfoils.These findings introduce a novel interaction mechanism between an inclined flapping airfoil and a fixed airfoil.Further analysis shows that this mechanism is valid at multiple plunging amplitudes and thus it may be utilized to enhance the lift in a three-dimensional(3D)scenario.Our findings reveal a novel lift-enhancing mechanism by tilting the stroke plane and may promote the design of MAV in this configuration.

关 键 词：微型飞行器 倾斜拍动平面 拍动翼 固定翼 格子玻尔兹曼方法 几何投影 增升 流动机制 

分 类 号：V21[航空宇航科学与技术—航空宇航推进理论与工程]