The acoustical properties of porous materials containing mean fluid flow
Abstract
A parallel-fiber model is presented here, describing sound propagation in rigid-framed porous materials with internal mean fluid flow. Expressions for the bulk acoustical properties of the porous material are obtained in terms of geometrical parameters - volume porosity, tortuosity and effective fiber radius - and in terms of the mean internal flow speed; fluid properties and acoustic frequency are, of course, also involved. Empirically determined steady-flow viscous and inertial flow-resistive coefficients are required in these expressions. Experimentally measured bulk properties are compared to predicted data both with and without mean flow and generally excellent agreement is noted.
- Publication:
-
Thermophysical Aspects of Re-entry Flows
- Pub Date:
- July 1986
- Bibcode:
- 1986aiaa.confT....C
- Keywords:
-
- Acoustic Properties;
- Ducted Flow;
- Fluid Flow;
- Mathematical Models;
- Porous Materials;
- Sound Transmission;
- Compressible Fluids;
- Flow Resistance;
- Flow Velocity;
- Glass Fibers;
- One Dimensional Flow;
- Urethanes;
- Wave Equations;
- Acoustics