旋翼前后行侧桨-涡干扰噪声辐射特性

BVI Noise Radiation Characteristics Across Advancing and Retreating Sides of Rotor

基于Beddoes修正尾迹模型,推导了一个新的旋翼桨-涡干扰(Blade-vortex interaction,BVI)噪声源方向性预测和BVI噪声辐射特性分析的模型,为更好地研究桨-涡干扰噪声的参数影响,提供了一套计算方法。该方法由移动的桨尖涡和旋转的桨叶相遇来确定桨-涡干扰的位置,由相交点的桨叶和涡线相对位置得出BVI夹角、轨迹马赫数等重要参数的计算公式。应用所建立的方法,首先针对有相关结果可供对比的BVI源发生位置进行了算例计算,以验证方法的有效性。然后,着重对直升机前飞状态的旋翼BVI噪声的发生进行了预测,深入分析了在旋翼前行侧和后行侧BVI噪声源的方向性和BVI噪声的辐射规律,并研究了前进比等参数对BVI噪声传播方向性的影响。在此基础上,得出了一些新的结论。

To study the parameter influences of the blade-vortex interaction（BVI） noise radiation based on Beddoes modified wake model,a new method is presented for the rotor BVI-source directionality prediction and its noise radiation characteristic analysis.In this method,the BVI location is determined by the encounter of the moving blade-tip vortex and the rotational blade.The formulas of some important parameters,such as the BVI angle and the trace Mach number,are derived by the encounter location of the blade and the vortex.To validate the method,the comparison of available results is made by applying the developed method.Then,an emphasis on detecting the occurrence of rotor BVI in forward flight is presented,and the BVI-source directionality and BVI noise radiation characteristics on both advancing side and retreating sides of the rotor are investigated.In addition,effects of different parameters,such as blade number and advanced ratio,are analyzed to investigate BVI noise propagation characteristics.From the above research,some new conclusions are obtained.