开式转子噪声数值模拟与试验研究

Numerical simulation and experimental measurement of open-rotor

为了研究开式转子在低速起飞工况下的噪声特性,运用计算流体力学(CFD)和计算气动声学(CAA)相结合的方法,对开式转子的离散噪声做了数值模拟。采用非线性谐波法(NLH)对开式转子的非定常流场进行计算,非定常分量和叶面定常载荷一同构建类比声源,最后使用FW-H积分法进行远场噪声辐射计算,获取远场多点的噪声频谱结果。搭建了开式转子试验台,使用0°~90°远场指向性阵列测试了指向角区间内的噪声特性结果,并与数值模拟结果进行对比。研究结果表明:干涉噪声是开式转子的主要噪声;关键频率处的数值模拟结果与试验结果趋势基本一致,误差在3 dB以内;所建立的非线性谐波法频域内展开求解非定常扰动量的气动噪声数值模拟方法,可以为开式转子噪声的快速准确预测提供一定的帮助。

In order to the study the characteristics of open-rotor noise in low speed,CFD(computational fluid dynamics)/CAA(computing aerodynamic acoustics)hybrid method of the open-rotor tone noise was set up.N-S equation is expanded by NLH method in the frequency domain,and the unsteady components are obtained.These unsteady components and steady load are used to construct Lighthill sound source.Finally,FW-H integration method is used to calculate far-field noise radiation.The noise experimental platform is built and test scheme is designed.The noise directivity in the range of 0°-90°is measured by using the far-field directivity array surround scale prototype.The characteristic of the noise of open-rotor is analyzed by comparing the numerical simulation results and experimental results.The results show that interaction noise is the major component of open-noise.The simulation results are basically consistent with the distribution trend of the experimental results at key frequency,the error is within 3 dB.The numerical simulation method of aerodynamic noise based on nonlinear harmonic method is developed to solve unsteady disturbance in frequency domain,which can provide some help for rapid and accurate prediction of open rotor noise.