Fluid–Structure Interaction Modeling of Flowfields Within Kevlar-Walled Wind Tunnels

Abstract

A detailed three-dimensional (3D) two-way coupled fluid–structure interaction simulation of a hybrid anechoic wind tunnel (HAWT) test section is presented with modeling all important effects, namely, turbulence, Kevlar wall porosity, and deflection. The complete 3D flowfield around a 3-ft chord NACA0012 placed into a HAWT test section is assessed. The Kevlar deflections are captured using finite element analysis, whereas 3D Reynolds-averaged Navier–Stokes computational fluid dynamics simulations are used to resolve the flowfield. Source terms are used to model the transpiration flow across the pores of the Kevlar fabric. Results are validated against an extensive experimental dataset. Aerodynamic properties of the airfoil are validated using airfoil pressure coefficients, airfoil wake pressure coefficients, and lift and drag coefficients. Boundary effects are validated against Kevlar wall pressure coefficients, Kevlar displacement, and transpiration velocity through the Kevlar fabric. Overall, a good agreement has been found among all comparisons presented. While some minor discrepancies were observed, these primarily stem from geometrical irregularities of the model and wind tunnel unresolved in the computational fluid dynamics. Overall, the fluid–structure interaction model now enables a detailed assessment of HAWTs to enhance their performance and can support experimental testing.