Numerical Computation of the Acoustic Pressure in a Coupled Covered Plate/Fluid Problem: Experimental Validation

This work deals with a coupled acoustic problem: a fluid contained in a cavity whose walls are all rigid except for the top, where a flexible plate is placed. The fluid is described by means of its pressure, whereas for the plate the Reissner-Mindlin model is used. A finite element method to solve this coupled problem, based on Lagrange hexahedral elements in the fluid and four node MITC elements in the plate, is presented. A comparison between numerical and experimental results is presented. Then, the behaviour of an absorbing layer attached to the plate is described by using a wall impedance condition and also by means of two different fluid equivalent models. Again, a comparison between numerical and experimental results is presented for the covered problem.