Optimal control of acoustic radiation power for a multiple-walled structure

Abstract

This paper is concerned with active control of acoustic radiation power of a multi-walled structure. In the past literature, optimal control of acoustic radiation power for a double-walled structure in which both walls of the acoustic space are surrounded by flexible walls has been studied. It has been clarified that the reduction level of an actively controlled double-walled structure is greater than that of an actively controlled one-walled structure in the sense of sound transmission control. Thus, the number of flexible walls have an impact on the control effect. However, research on modelling and control of a triple or more walled structure have not sufficiently done. Therefore, this paper presents how to model and control a triple walled structure. First, the target structure is analytically modelled by using modal coupling method that utilizes modal amplitudes of the uncoupled subsystems. Next, the optimal control law for minimizing the acoustic radiation power of the triple wall structure is derived by using the elementary radiator method which calculates the acoustic radiation power based on the minute and divided elements of the panel. Finally, numerical simulations of the control system are conducted, confirming the effectiveness of the proposed method.