Active Control of Structure-Borne and Airborne Sound Transmission Through Double Panel

This paper presents a theoretical study of the active control of both structure-borne and airborne noise transmission through a double-panel system. The physical and geometrical characteristics of the system were chosen to be similarto those of the fuselage of a civil aircraft. The total sound power transmitted by the double-panel system was used to evaluate the active control performance of four different strategies for the control system: e rst, active mounts connecting the two panels and loudspeakers placed between the two panels were driven to minimize the total sound powerradiated by thepanel (thereference case );second, activemounts connecting the two panels were driven to cancel the out-of-plane velocities at the connecting points on the radiating panel; third, loudspeakers placed between the two panels were driven to cancel the acousticpressure at points neareach control loudspeaker; and fourth, active mount and control loudspeaker systems were used simultaneously as already stated. The simulations show that the control loudspeakers are able to produce large attenuation of the sound transmission at low frequencies close to the mass-air-mass resonance of the double panel. The performance is signie cantly better if the loudspeakers are driven to minimize radiated sound power, rather than cancel pressure between the panels. The active mount cone guration studied in this paper does not producesignie cant reductions of the sound transmission except in the case where it is used in combination with the control loudspeakers. I. Introduction