Simulation of Viscothermal Losses on the Acoustic Behaviour of a Thin Fluid Layer Enclosed between Two Oscillating Plates

Abstract

This article deals with a theoretical investigation for the analysis of a double-plate system enclosing a viscothermal fluid cavity. Dynamic equations of the coupled system are established in appropriate dimensionless form including the effects of viscosity and thermal conductivity of the fluid. The pressure wave equation is derived in in-plane form. This equation is solved analytically in the case of oscillating plate motions in order to determine the acoustic pressure in the cavity. Numerical results are presented for the case of two modal shapes. They show the importance of the viscothermal effects in the case of thin fluid layers.