低雷诺数下翼面局部振动增升机理研究  

Lift enhancement mechanism for local oscillation of airfoil surface at low Reynolds number

作　　者：康伟[1] 刘磊[1] 徐敏[1] 雷鹏飞[2] 张家忠[2] 

机构地区：[1]西北工业大学航天学院,西安710072 [2]西安交通大学能源与动力工程学院,西安710049

出　　处：《航空学报》2015年第11期3557-3566,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11402212);中央高校基本科研业务费专项资金(3102014JCQ01002)~~

摘　　要：采用计算流体力学(CFD)方法研究低雷诺数下翼面局部振动对翼型气动特性及其流动特征的影响规律。建立局部振动激励的力学模型,并采用任意拉格朗日-欧拉坐标系下的特征线有限元(ALE-CBS)方法对局部振动激励下翼型绕流问题进行模拟,分析局部振动对非定常流动演化的影响规律,揭示其增升机理。研究结果表明:翼面局部变形的增加会有效降低翼型上表面的前缘压力;非定常流动分离中旋涡之间的距离及其演化频率与振动频率的关系是影响翼型翼面局部振动增升效果的重要因素。当流场主频率与振动频率相同,次要频率为主频率的2倍,即发生锁频时,翼面振动产生的移动分离泡能够使分离区从主流获取更多的能量,使翼型上表面保持较低的压力,有效提高翼型升力。Aerodynamic performance and the related flow patterns are studied for low Reynolds number flow with local oscillation of airfoil surface using computational fluicl dynamics（CFD）method.The model of local oscillation of airfoil surface is established and flow around the airfoil under the oscillation is simulated by arbitrary Lagrangian Eulerian-characteristic based split（ALE-CBS）algorithm.The effect of the local oscillation on flow evolution is highlighted to reveal the mechanism for lift enhancement.The results show that the local deformation of the surface reduces the suction pressure on the leading edge efficiently.Moreover,the crucial factors for lift enhancement of local oscillation are the distance between the vortices in the flow separation zone and the relationship between the oscillating frequencies and frequencies of vortex formation.The moving separation bubbles can transfer more energy from the main stream to keep a lower pressure on the upper surface so that the lift of the airfoil is improved effectively,as the primary frequency of flow equals the oscillating frequency and the second order frequency of the flow is twice of the first one,i.e.frequency lock-in occurs.

关 键 词：低雷诺数流动 局部振动 锁频 流动分离 增升 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]