Computational Method for Describing Porous Wall Boundary Conditions Based on Experimental Data

Abstract

A computational and experimental study has been undertaken to investigate methods of modeling solid and porous wall boundary conditions in computational fluid dynamics (CFD) codes. The procedure utilizes experimental pressure measurements at the walls to develop a flow-fleld solution based on the method of singularities. This solution is then imposed as a pressure boundary condition in a CFD simulation of the internal flowfield. The effectiveness of this method in describing the boundary conditions at the wind-tunnel walls using only sparse experimental measurements has been investigated. Verification of the approach using computational studies has been carried out using an incompressible flow solver. The current work demonstrates this technique for low-speed flows and compares the result with experimental data obtained from a heavily instrumented variable porosity test section. Position and refinement of experimental measurements required to describe porous wall boundary conditions has also been considered for application to other porous wall wind tunnels. The approach deveioped is simple, is computationally inexpensive, and does not require extensive or intrusive measurements. It may be applied to both solid and porous wall wind-tunnel tests.