基于时域声辐射模态的结构噪声主动控制研究

以简支矩形板为例，提出了利用时域声辐射模态进行声辐射研究，并从物理和数学意义上对时域声辐射模态进行了解释。研究表明时域声辐射模态既与时间无关，也互相独立，使得计算和控制声功率得以简化。针对瞬时声功率主要由第一阶辐射模态的声功率所决定的特点，在时域里进行结构噪声的主动控制研究，通过抵消第一阶辐射模态的声功率使得总的声功率得以有效降低。在此基础上，建立基于最小二乘算法的自适应反馈控制系统，进行仿真计算，结果证明了主动控制策略是有效的。

Study on Active Control of Structural Noise Based on Acoustic Radiation Modes in Time Domain

A new method for analysis of exterior sound radiation problem is developed by means of acoustic radiation modes in time domain.The physical characteristics and mathematical meaning of the radiation modes are presented.In the time domain,a new formulation is developed for calculating the radiation modes of a baffled planar source.These modes are only dependent on the radiator geometry,and independent on time.According to the fact that the sound power of the first radiation mode is dominant in transient sound power,a control strategy in time domain is developed in which by minimizing the adjoint coefficent of the first radiation mode,the sound power of the first radiation mode is decreased effectively.Finally,an adaptive feedback control system based on LQR algorithm is developed to control the adjoint coefficient of the first radiation mode.The simulation result verifies that the proposed method can actively suppress transient structural acoustic radiation.