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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。
Computational fluid dynamics (CFD) method is used to study the influence of local vibration on airfoil aerodynamic characteristics and flow characteristics under low Reynolds number. The mechanical model of local vibration excitation is established and the ALE-CBS method is used to simulate the flow around the airfoil under local vibration excitation. The regularity of the influence of steady flow evolution reveals the mechanism of its increase. The results show that the increase of the local deformation of the airfoil can effectively reduce the leading edge pressure on the upper surface of the airfoil. The relationship between the vortex shedding distance and the evolution frequency and the vibration frequency in unsteady flow separation is the influence of the local vibration of the airfoil Ascension of the important factors. When the main frequency of the flow field is the same as the vibration frequency, the secondary frequency is twice that of the main frequency, that is, when the frequency locking occurs, the moving separation bubble generated by the vibration of the airfoil can make the separation area obtain more energy from the mainstream, The surface to maintain a lower pressure, effectively improve the airfoil lift.