有源吸声结构近场声学特性

有源吸声结构是近年来提出的一种利用有源控制技术吸收低频反射声的智能结构,对其近场声学性能的分析将为系统优化设计、次级源和误差传感器布放及控制目标选取等关键问题提供理论支持。本文在最小反射声功率条件下,对控制前后吸声结构近场观察面声强及吸声系数的变化进行数值仿真。仿真结果从近场法向声强的幅值、辐射形式及空间分布等方面分析有源吸声结构的近场声学特性,并从结构表面吸声系数变化的角度进一步加以验证。

Near-Field Acoustic Performance of Active Sound Absorption Structures

Active sound absorption structure proposed in recent years is viewed as a feasible approach to effectively absorb low-frequency reflected sound. Analyzing the near field acoustic performance can offer theoretical help for some key issues, such as design optimization, the arrangements of secondary sources and error sensors, and selection of the control objective. Under the minimization of the reflected sound power output, the changes of sound intensity and absorption coefficient on the near field of the structure before and after control are investigated by numerical simulations. Near-field acoustic performances of active sound absorption structure are analyzed through the amplitude, radiation form and dimensional distribution of normal sound intensity. The changes of absorption coefficient on structure surface more validate near-field acoustic performances of active sound absorption structure.