结构噪声主动控制在时域声辐射模态下的仿真研究

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。研究表明时域声辐射模态既与时间无关，且互相独立，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，建立了时域声辐射模态的状态空间方程，对该方程的性能进行了分析，并利用最优控制算法的自适应反馈控制系统进行仿真计算。最后讨论了不同情况下的计算精度，并对影响仿真结果的因素进行了分析。

Active control of acoustic radiation based on time radiation modes

A new method for the analysis on the problem of the exterior sound radiation from a rectangular baffled planar source is developed by means of the method of time domain acoustic radiation modes. Within the time domain, being time-invariant, the modes depend only on the radiator geometry. According to the fact that the sound power of the first radiation mode is the dominant for transient sound power, a control strategy in time domain is developed, in which by canceling the adjoint coefficent of the first radiation mode, the sound power of the first radiation mode is decreased effectively. And then, a simulation within the state space is done. In order to control the adjoint coefficient of the first radiation mode, an adaptive feedback control system based on optimal control algorithm is developed. In all kinds of circumferences, the sound power for the time domain sound radiation modes is estimated. Finally, the availability of the control strategy is confirmed via a software.