航空发动机风扇管道径向声模态模拟与识别技术

针对航空发动机风扇管道径向声模态模拟与测试问题，研究了径向声模态模拟技术以及径向声模态识别技术。采用基于径向排布的声源阵列形式，调节阵列预设的各扬声器幅值及相位实现径向模态声源模拟。建立声源管道下游多圈环形阵列，根据阵列位置信息构造求解模态的传递函数矩阵，运用Tikhonov正则化方法减小传递函数矩阵的条件数，从而实现径向声模态识别能力。通过理论推导和数值计算，设计风扇管道径向声模态试验装置，并在消声室进行试验验证。通过试验验证了该系统具备周向4阶以内，径向2阶以内的径向声模态模拟与识别能力。

Simulation and analysis of the in-duct radial acoustic modes in aero-engine fan pipe

For simulation and testing of the radial acoustic modes of aero-engine fan pipe, the simulation and identification methods of the radial acoustic modes are studied. The radial mode sound source is simulated by adjusting the amplitude and phase of each loudspeaker preset in the array. The multi-cycle ring array downstream of the sound source pipeline is established, and the transfer function matrix of the mode is constructed according to the position information of the array. The Tikhonov regularization method is used to reduce the number of conditions of the transfer function matrix, so as to realize the capability of radial acoustic mode recognition. Through theoretical deduction and numerical calculation, the radial acoustic mode test device of fan pipe is designed and verified in anechoic chamber. The experimental results show that the system has the ability to simulate and identify radial acoustic modes within 4 circumferential order 4 and radial order 2.