旋翼悬停状态形变特性及其对噪声的影响  

Deformation characteristics of a hovering rotor and its influence on the aerodynamic noise

作　　者：李志彬 曹亚雄 林永峰[1] 孙伟[1] 袁明川[1] LI Zhibin;CAO Yaxiong;LIN Yongfeng;SUN Wei;YUAN Mingchuan(Science and Technology on Rotorcraft Aeromechanics Laboratory,China Helicopter Research and Development Institute,Jingdezhen 333001,China)

机构地区：[1]中国直升机设计研究所直升机旋翼动力学重点实验室,景德镇333001

出　　处：《空气动力学学报》2022年第5期71-78,共8页Acta Aerodynamica Sinica

基　　金：国防基础科研计划(JCKY2019205D002);航空科学基金项目(20200057002001)。

摘　　要：为研究桨叶弹性形变对旋翼气动噪声的影响,基于CamradⅡ软件和FW-H方程,建立了考虑桨叶弹性形变的旋翼悬停气动噪声计算模型。其中,桨叶弹性形变量采用CamradⅡ的弹性桨叶模型计算,形变桨叶外形采用三维网格精确描述,结合CamradⅡ计算得到的旋翼非定常气动载荷,最后基于FW-H方程进行了形变旋翼悬停噪声的计算分析。同时,在风洞中采用双目立体视觉方法对模型旋翼进行形变测量试验,通过CamradⅡ的仿真数据与试验数据的对比分析,发现仿真数据与试验数据基本吻合,验证了CamradⅡ具有较好的可靠性,能够准确预估悬停状态下桨叶的弹性形变量。全尺寸旋翼的悬停噪声计算结果表明:在典型工作状态下,旋翼桨叶会发生明显的弹性形变,尤其在挥舞方向;桨叶形变不会改变旋翼悬停气动噪声的方向特性;在噪声的主要传播方向上,桨叶形变对厚度噪声和载荷噪声均会产生作用,进而导致总噪声的最大变化量约1.0 dB。通过本文研究表明,在对旋翼气动噪声,尤其是载荷噪声成分进行精确计算时,考虑桨叶的弹性形变是非常必要的。In order to study the influence of blade elastic deformation on rotor aerodynamic noise, based on Camrad Ⅱ and the FW-H equation, an aerodynamic noise calculation model that takes the blade elastic deformation into account has been established for a rotor in hover. The elastic blade model in Camrad Ⅱ is used to calculate the elastic shape variation of the blade. A three-dimensional grid is used to accurately describe the deformed blade. Combined with the unsteady aerodynamic load of the rotor obtained by Camrad Ⅱ, the hovering noise of the deformed blade is calculated and analyzed based on the FW-H equation. The binocular stereo vision method is used to measure the deformation of the model rotor in a wind tunnel. It is found that the numerical results are agree reasonably well with the experimental data, which verifies that Camrad Ⅱ has a good reliability and can accurately predict the elastic shape variation of the blade in hover. The hover noise characteristics of the full scale rotor are further calculated and analyzed. The results show that under typical working conditions, the rotor blade has obvious elastic deformation, especially in the flap direction. The blade deformation does not change the directivity of the noise in hover. However, it affects the thickness and loading noise in the main propagation direction, resulting in a maximum variation of about 1.0 dB in the total noise. Consequently, the influence of the blade elastic deformation should be considered for obtaining more accurate aerodynamic noise.

关 键 词：旋翼噪声 桨叶弹性形变 CamradⅡ FW-H方程 悬停状态 

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]