Experiments on Actively Suppressing Sound Reflection and Radiation by a Piston in a Water-Filled Pipeline

Abstract—The physical foundations of an acoustic active cancellation system (ACS) that suppress self-radiation and reflection of sound is considered, which uses a local negative feedback (NF) method for acceleration. ACS with control of the total and incident field are compared. The possibility of controlling the acoustic impedance of the surface by changing the NF value for acceleration is demonstrated. Experiments were carried out with a single-channel ACS with control of the total field under conditions simulating normal incidence of a plane sound wave on a plane reflector. The results demonstrate the possibility of deep suppression of reflected and radiated waves. The stabilizing role of local NF has been experimentally confirmed.