Modeling a Waveguide with a Source and Receiver of Oscillations in the Presence of Impedance Attenuation

An acoustic waveguide with a source and receiver of oscillations with impedance damping on the wall of the waveguide and a viscoelastic gasket in the zone of fastening of the oscillation receiver is considered. The harmonic mode of oscillations in the waveguide is induced by generating oscillations of piezoceramic transducer, the electrodes of which are supplied with difference of potentials harmonic type. Waves from the acoustic part of the waveguide are registered by a piezoceramic receiver. The emitter and receiver were modeled by one-dimensional equations of the theory of electroelasticity and an axisymmetric problem was considered for an acoustic fluid. The presence of impedance boundary conditions on the side surface of the waveguide gives rise to a spectral problem in which one complex root was determined because the source and receiver operate on thickness vibration mode. The boundary conditions for the receiver are supplemented by the equation of current flow through the external circuit due to the choice of the complex conductivity of the external circuit. Numerical experiments have shown that taking damping into account on the side wall affects not only the resonant frequency but also the current on the receiver electrodes. The viscoelasticity of the damping gasket affects only the amplitude of the current but does not affect the frequency.