Acoustic radiation by a vibrating cylindrical shell with an impedance covering

An analysis is made of the possible acoustic insulation of a vibrating surface under conditions corresponding to underwater-sound experiments by covering the outside of the surface with a thin covering of an acoustically soft material. A theoretical analysis is made of the vibrations of an infinite cylindrical shell having nodal lines parallel to the axis on the surface of the cylinder. It is found that the radiation can be reduced for each vibrational mode in a certain frequency range, governed by the geometry of the cylindrical surface and covering and by the properties of the covering material.