VM306
VM306
Surface Impedance for a Single Poroelastic Layer
Overview
| Reference: | Atalla, N. et al. "A Mixed Displacement-Pressure Formulation for poroelastic Materials." Journal of the Acoustical Society of America. 1998: 1444-1452. |
| Analysis Type(s): | Harmonic (ANTYPE = 3) |
| Element Type(s): | 3D 20-node Acoustic Solid (FLUID220) |
| Input Listing: |
vm306.dat
VM306 requires a supplemental .cdb input file which is too long to include full input listings. This file must be downloaded and placed in your working directory for the test case to run properly. Additionally, the geometry and mesh should be regenerated. Download link: MAPDL Test Case Files for 2024 R2 vm306.cdb |
Test Case
A laterally infinite glass wool layer attached onto a rigid impervious wall is modeled as a brick with the lateral displacements set to zero to simulate the laterally infinite extent. A normal incidence plane wave of unit amplitude is loaded on the surface of the glass wool. The surface impedance of the glass wool is calculated and compared with the reference solution. Determine the surface impedance of the glass wool.
| Material Properties | Geometric Properties | Loading |
|---|---|---|
|
Speed of sound = 342.2m/s Density = 1.21 kg/m3 Young’s modulus = 4400 kPa Poisson’s ratio, ν = 0.0 Fluid resistivity = 4000 Ns/m4 Porosity = 0.94 Tortuosity = 1.06 Viscous characteristic length = 0.56e-4 m Thermal characteristic length = 1.10e-4 m Bulk density of solid phase = 130 kg/m3 Loss factor of elasticity moduli = 0.1 Biot’s coefficient = 1.0 Bulk modulus of the elastic solid = 0 Pa |
Thickness h = 10 cm | Normal incidence plane wave acoustic pressure P = 1 Pa |