管道内的旋转声源是各种叶轮机械气动噪声的主要来源，基于传声器阵列测量技术对其进行识别是掌握叶轮机械气动噪声产生机理与辐射规律的重要手段。但是现有的基于传声器阵列测量的波束形成技术和频域近场声全息技术均无法高效且高分辨率地识别管道内的旋转声源，鉴此，本项目拟研究一种时域近场声全息技术实现该目的。首先，基于压缩感知原理提出一种稀疏采样条件下的时域旋转框架技术，以较低测量成本实现测量声压中多普勒效应的消除，在此基础上提出理想条件下的管道内时域等效源法近场声全息，继而将其扩展至管道内复杂边界条件下和复杂流场环境下的旋转声源识别，并针对其中的非稳定性问题，提出有效的控制方法，最终形成完善的适用于管道内旋转声源识别的时域近场声全息理论。基于以上理论，研制相应的测量分析系统，开展实验研究。本项目研究成果有望推动管道内旋转声源识别理论的发展，并为叶轮机械的声学优化设计和噪声的主被动控制提供重要的技术手段。

Rotating sound sources in a duct are the main factors causing the aeroacoustic noise from turbomachinery, and their identification based on the data measured by a microphone array can provide an important means for studying the generation mechanism and radiation pattern of aeroacoustic noise. However, the present Beamforming and frequency-domain nearfield acoustic holography cannot realize an efficient and high-resolution identification of rotating sound sources in a duct. In view of that, a time-domain nearfield acoustic holography will be proposed in this project. Firstly, a time-domain spinning frame will be built based on the compressive sensing theory to eliminate the Doppler effects from the measured pressure at a low cost. On that basis, an in-duct time-domain equivalent source method is to be developed for identifying rotating sources in an ideal duct, and then extended to the ducts with complex boundary conditions and complex flow fields. The instability problem occurred in the in-duct time-domain equivalent source method will be also investigated and its effective controlling means will be found. Based on these theoretical studies, a measuring and analyzing system will be developed and utilized for experimental studies. It can be expected from the studies in this project to promote the development of the identification theory for in-duct rotating sound sources, and to provide an important technical approach for acoustic optimization design as well as active and passive noise control in turbomachinery.