The existence of internal acoustic radiation modes in a cylindrial acoustic cavity

Abstract

The external acoustic radiation operator maps a boundary-valued quantity, such as the normal surface velocity of a radiator, to the pressure radiated into the field. It has been shown that the decomposition of the acoustic radiation operator results in a set of orthogonal singular velocity patterns or acoustic radiation modes. It has also been demonstrated that superposition of selected acoustic radiation modes can be used to prescribe surface velocity distributions resulting in poor radiation of pressure into the field. The development of acoustic radiation modes for the interior cavity problem may provide insight into the physics of structural acoustic coupling between, for example, a thin cylindrical shell and the enclosed acoustic volume. However, the existence of these radiation modes for the interior problem is uncertain. Also, if these interior radiation modes do exist, do they in fact coincide with the acoustic cavity or normal modes? This study intends to explore the existence of acoustic radiation modes for the interior cavity problem and their relationship to the cavity modes of a right circular cylindrical acoustic volume of air.