利用近场法向声能流调控远场低频线谱噪声的自适应控制方法

Adaptive control method for low-frequency line spectrum noise based on normal intensity

针对水下结构远场低频辐射噪声的控制问题,提出了基于水下结构近场法向声能流的噪声自适应控制方法。该方法以结构近场的法向声能流作为控制物理量,利用有源控制系统自适应调节次级声源,抑制结构法向方向上的能量传播,实现远场低频辐射噪声控制。以圆柱壳为模型的试验结果表明,在1000~3000 Hz的频段内,相比于传统的以近场声压作为控制物理量的有源控制方法,能流法能够在保证总辐射声功率不升高的前提下,实现远场周向52.8%~76.3%区域内的噪声控制,且频率越低,降噪范围越广。

A noise adaptive control method based on the normal acoustic energy flux of underwater structures is proposed to control low-frequency radiation noise in the far-field of underwater structures.The method utilizes the normal acoustic energy flux in the near-field of the structure as the control physical quantity,and adaptively adjusts the output of the secondary sound source using an active control system to suppress the energy propagation in the normal direction of the structure,thereby achieving reduction of lowfrequency radiation noise in the far-field.The experimental results,based on a cylindrical shell model,indicate that within the frequency range of 1000 Hz to 3000 Hz,the energy flux control method,as opposed to the traditional active control method using near-field sound pressure as the primary control parameter,can achieve noise reduction in the azimuthal direction in the far-field area from 52.8%to 76.3%,while ensuring that the total radiated acoustic power remains unchanged.Furthermore,as the frequency decreases,the noise reduction range becomes wider.