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结合试验及数值模拟方法对具有改进型CLOR(CLOR-II)桨尖模型旋翼悬停状态气动噪声特性进行研究。在CLOR桨尖旋翼基础上,兼顾旋翼噪声特性和气动性能,对旋翼气动外形进行改进。为在获得高气动性能(大拉力)的同时限制旋翼气动噪声的过快增长,采用曲线前后掠组合、尖削及多种翼型分段配置等设计方法,以抑制跨声速流范围,达到降低气动噪声的目的。作为参考验证,文中还同时进行了相同实度的矩形桨叶、常规后掠新型桨尖的旋翼气动噪声特性的测量试验。考虑到传播距离和方向角(与桨盘平面的夹角)等因素对噪声辐射特性的影响,试验中对不同观测点的噪声进行了测量。同时为反映桨尖马赫数(压缩性)对旋翼噪声特性的影响,还测量了多种转速下的旋翼噪声特性。为充分分析新型桨尖旋翼的噪声特性,本文采用了基于CFD/Kirchhoff方法的旋翼噪声分析方法对试验中较难开展的高桨尖马赫数状态进行预估分析,分别给出了上述不同桨尖旋翼表面等马赫线、近场声压时间历程等跨声速流场细节。通过试验与数值分析,得出了关于CLOR-II型桨尖旋翼气动噪声特性的影响规律,与参考旋翼相比验证了该新型桨尖旋翼在提高气动性能的同时具有良好的噪声特性。
The aerodynamic noise characteristics of the rotor hovering state with the improved CLOR (CLOR-II) tip model are studied by means of combining experiments and numerical simulation. On the basis of the CLOR tip rotor, taking into account the rotor noise characteristics and aerodynamic performance, the rotor aerodynamic profile is improved. In order to limit the excessive aerodynamic noise of the rotor while achieving high aerodynamic performance (high tensile force), the design method of curve front-back sweep combination, taper cutting and multiple airfoil segment configurations are adopted to reduce the range of transonic flow and to reduce The purpose of aerodynamic noise. As a reference verification, the same real degree of rectangular blade, conventional swept new tip of the rotor aerodynamic noise measurement test. Taking into account the influence of the propagation distance and the azimuth angle (the angle with the plane of the propeller disk) on the radiation characteristics of the radiation, the noise of different observation points was measured in the experiment. At the same time, in order to reflect the effect of tip Mach number (compression) on the rotor noise characteristics, the rotor noise characteristics at various speeds were also measured. In order to fully analyze the noise characteristics of the new tip rotor, this paper uses the rotor noise analysis method based on the CFD / Kirchhoff method to predict and analyze the Mach number condition that is difficult to be carried out in the experiment. The different tip Rotor surface Mach line, near-field sound pressure time history and other transonic flow field details. The influence of aerodynamic noise on CLOR-II tip rotor is obtained by experiments and numerical analysis. Compared with the reference rotor, the new tip rotor has good aerodynamic performance while improving aerodynamic performance.