直升机旋翼涡环状态的气动噪声特性  

Investigation of helicopter rotor aeroacoustic characteristics in vortex ring state

作　　者：王亮权 何龙[1,3] 徐国华 杨仕鹏[1] 李丹 WANG Liangquan;HE Long;XU Guohua;YANG Shipeng;LI Dan(Laboratory of Rotor Aerodynamics,China Aerodynamics Research and Development Center,Mianyang 621000,China;National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]中国空气动力研究与发展中心旋翼空气动力学重点实验室,绵阳621000 [2]南京航空航天大学直升机旋翼动力学国家重点实验室,南京210016 [3]北京航空航天大学航空科学与工程学院,北京100191

出　　处：《空气动力学学报》2022年第6期83-91,共9页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(11902335);中国空气动力研究与发展中心基础和前沿技术研究基金(PJD20180146)。

摘　　要：使用一种鲁棒的CFD/涡粒子耦合方法,以Caradonna-Tung旋翼为研究对象,采用固定旋翼总距、逐步增大垂直下降率的计算策略,对直升机旋翼垂直下降时可能出现的涡环状态进行了数值模拟,展示了旋翼涡环状态高度紊乱的流场。数值模拟结果同时表明,旋翼垂直下降速度接近悬停诱导速度时,旋翼进入深度涡环状态,整体拉力及桨叶剖面的升力迅速下降。在流场模拟结果的基础上进行了旋翼气动噪声分析,结果表明随着垂直下降率的增加,旋翼载荷噪声频谱特性出现显著变化,频谱阶次在十倍频以上的中频噪声幅值有所提高。基于这一发现,提出了一种在直升机机身周围安装麦克风,通过实时分析旋翼噪声频谱成分,以对旋翼在进入涡环状态的早期就做出及时预警的新方法。A robust CFD/vortex particle coupling numerical method for simulating the three-dimensional flow field of a helicopter rotor is established in the present study.Taking the Caradonna-Tung rotor as the research model,the vortex ring state appeared in the vertical descent flight is simulated with the strategy of gradually increasing the vertical descent rate at a fixed collective pitch.The simulation successfully reveals the highly turbulent flow field around the rotor in the vortex ring state.Numerical simulation results also show that the rotor enters the deep vortex ring state when the vertical descent rate approaches the hovering induced velocity,where the rotor thrust and the lift force at each blade section decrease rapidly.Based on the numerical simulation data,the aerodynamic noise characteristics of the rotor are analyzed.With the increase of the vertical descent rate,the frequency spectra of the loading noise change dramatically,and the amplitude of noise with intermediate frequencies more than 10 times higher than the fundamental frequency increases.Based on this finding,a new method of installing microphones on the helicopter fuselage is proposed,which can provide a timely warning of the rotor encountering the vortex ring state by a real-time analysis of the rotor noise spectrum components.

关 键 词：直升机旋翼 垂直下降 涡环状态 气动噪声 耦合方法 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]