悬停状态下旋翼噪声声源反演的正则化方法

根据旋翼辐射的气动噪声求解气动声学反问题，给定合理的旋翼表面载荷并结合声类比方法得到观测点的信号，以此进行表面载荷反演。对建立的大型不适定性方程组采用奇异值分解结合正则化方法进行求解，为克服反演结果存在的数值振荡，采用多项式函数来表示未知量，并引入库塔条件作为先验信息。结果表明:理想条件下，该方法得到的旋翼表面的压力分布更接近输入值，尤其在载荷分布较大的叶尖区域，考虑干扰噪声影响后，该方法得到的展向截面吸力峰位置的最大相对误差从15%减小到4%。 

Regularization method for subsonic hovering rotor sound source reconstruction

The aeroacoustic inverse problem was solved according to the aeroacoustic noises radiated by the rotor. The blade surface loading was given and acoustic analogy method was used to obtain the observation data. A large set of ill-posed equations were solved by singular value decomposition combined with the regularization method. In order to overcome the obvious numerical oscillations, a polynomial function was used to represent the unknown, at the same time the Kutta condition was introduced as a priori information. The results showed that under ideal condition, the pressure of the rotor surface obtained by this method was closer to the input value, especially in the tip region. Under certain interference noise, the maximum relative error of the pressure peak position obtained by this method was reduced from 15% to 4%.