激励参数对横流中合成射流绕流场的影响

Effects of excitation parameters on flow field around synthetic jet in cross-flow

为了将合成射流用于垂直轴风力机叶片表面流动控制,采用数值模拟方法,以平板上的合成射流为研究对象,分析横流中合成射流和连续射流的流场特征,比较3种激励频率和3种速度比时合成射流的绕流场。结果表明:速度比相同时,合成射流对边界层作用效果优于连续射流;合成射流在吹吸气不同时刻对边界层作用方式不同;合成射流在横流中的发展轨迹受速度比和激励频率的影响。速度比越大,孔口附近射流轨迹斜率越大;激励频率越大,孔口附近射流轨迹斜率越小。

To use synthetic jets for surface flow control of vertical axis wind turbine blades,it is necessary to understand and master the interaction rules between synthetic jets and boundary layers.In this paper,a numerical simulation method is employed to study the synthetic jet on a flat plate and to analyze the flow field characteristics of synthetic and continuous jets in a cross-flow.The effects of synthetic jet on the flow field at three excitation frequencies and three velocity ratios are compared.Our results show when the velocity ratio is the same,the effect of synthetic jet on boundary layer is better than that of continuous jet.The synthetic jet acts on the boundary layer in different ways at different moments of blowing and inhaling.The development trajectory of the synthetic jet in the cross-flow is affected by the velocity ratio and the excitation frequency.When the velocity ratio is larger,the slope of the jet trajectory near the orifice is larger.When the excitation frequency is larger,the slope of the jet trajectory near the orifice becomes smaller.