Aerodynamic performance of a porous airfoil

Abstract

Trailing edge noise is considered as a significant source of airfoil self-noise. A potential passive technique for reducing the turbulent trailing edge noise produced by rotating wind turbines blades is using porous airfoil designs. However, this can impact on their aerodynamic performance. In this work, the aerodynamic performance of a S809-type porous airfoil is investigated numerically using the open source finite volume code OpenFOAM. The simulation is carried out for 2-D airfoils using the k-ω SST RANS turbulence model and assuming incompressible flow. Several porous materials with different permeability values are investigated at different angles of attack. The flow within the porous airfoils is modelled using the Darcy-Forchheimer model that adds a source term to the momentum equation to account for pressure drop through the porous material. The methodology is validated by comparison with experimental data for a SD7003 porous airfoil. Preliminary results for a S809 airfoil show that the lift force decreases and drag increases with increasing permeability as expected.