尾缘襟翼对扑翼的获能特性影响  

Effects of trailing-edge flaps on the power-extraction performance of flapping airfoils

作　　者：周大明 孙晓晶[1] ZHOU Daming;SUN Xiaojing(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《空气动力学学报》2021年第5期7-18,共12页Acta Aerodynamica Sinica

摘　　要：扑翼获能器是一种模仿飞鸟振翅扑动的新型获能装置。为提高扑翼的获能效率,建立了一种带有尾缘襟翼的扑翼模型,且该种襟翼在扑翼运行过程中始终向翼型压力面偏转,利用计算流体力学方法求解了二维不可压缩非稳态Navier-Stokes方程。在雷诺数Re=4.7×10^(5)的工况下,分析了尾缘襟翼对扑翼流场的作用机理,并与原始翼型扑翼进行了对比。同时,还研究了翼型厚度对具有尾缘襟翼扑翼获能的影响。结果表明:扑翼升沉力做功占其获能的主要部分,应用尾缘襟翼后,扑翼的升沉力在整个扑动周期内都得到了提高,并且升沉力与升沉速度的协同性获得改善;尾缘襟翼对扑翼获能效率的提高作用在高频率下效果最为明显,最多可以得到23.5%的相对提升;此外,翼型厚度影响着扑翼前缘涡的演化,翼型厚度增加,前缘涡的生成受到抑制,扑翼获能效率则随翼型厚度增大呈先增加后降低的规律,因此存在最佳翼型。The flapping airfoil is a new type of energy harvester inspired by the flapping motion of birds.This paper aims to explore the potential of power-extraction enhancement of a flapping airfoil by using an oscillating trailing-edge flap,which invariably deflects towards the pressure side of the airfoil during the flapping cycle.Two-dimensional unsteady Reynolds-averaged Navier-Stokes(URANS)simulations at a Reynolds number Re=4.7×10^(5) are conducted to compare the power-extraction performance of the proposed model with that of a plain flapping airfoil.In addition,the effect of airfoil thickness on the power-extraction efficiency is also analyzed.The results show that the heaving force,which can be increased during the entire flapping cycle by the use of trailing-edge flap,is the dominant contributor to the total power output of a flapping airfoil.It is also found that a better synchronization between the heaving motion and heaving force can be achieved by the use of a flap,yielding a greater power-extraction efficiency.The trailing-edge flap is proved to be beneficial to the power generation,especially at higher frequencies.The maximum power-extraction efficiency of the flapping airfoil with a trailing-edge flap can be increased by approximately 23.5%compared to the plain airfoil.Moreover,the leading-edge vortex will be suppressed by thicker airfoils,and there is an optimal airfoil thickness for the power extraction.

关 键 词：扑翼 获能 尾缘襟翼 前缘涡 翼型厚度 计算流体力学 

分 类 号：V276[航空宇航科学与技术—飞行器设计]