航空发动机压气机管道声模态无偏稀疏重构方法

To overcome the difficulty of a large number of sensors required for a uniform circular array and low accuracy of traditional sparse estimation methods when applying acoustic mode decomposition technology to analyze the characteristics of intercepted acoustic modes within compressor ducts， this paper proposes an unbiased sparse acoustic mode reconstruction method which solves for the support set of the acoustic mode solution vector using L₁-norm regularization and achieves unbiased estimation of modal amplitudes through least squares. The superiority of the proposed method is validated through both simulation analysis and experimental research. The results indicate that the unbiased sparse reconstruction method proposed in this paper significantly improves the accuracy of acoustic mode reconstruction and demonstrates better robustness compared to classic sparse reconstruction method. Compared to the L₁ norm regularization method， the reconstruction accuracy of dominant acoustic mode amplitude is improved by 1.74 dB， 2.36 dB and 0.78 dB under three different sensor layouts， respectively. Compared to the L_1/2 norm regularization method， it has better robustness in order identification.