Waveguide Sound Insulation in Pipes Lined with Elastic Waterlike Material

The paper considers effect of an elastic waterlike layer placed on the wall of a water-filled waveguide on sound propagation in the waveguide. Shear oscillations excited in the layer change the effective conductivity of the waveguide wall. In a certain frequency range near the resonance frequency, the wavenumber of the sound wave is purely imaginary: the wave attenuates exponentially. The results of calculating the effectiveness of this effect are presented, and an analogy with the well-known waveguide insulation effect is drawn.