Computation of aerodynamic coefficients for a flexible membrane airfoil in turbulent flow: A comparison with classical theory

Abstract

In the present paper an aeroelastic model of flexible membrane wing aerodynamics which incorporates the Reynolds-averaged Navier–Stokes equations is presented. The Reynolds stresses are prescribed by the k–ω shear-stress transport eddy-viscosity model recently proposed by Menter. The computed coefficients are compared with classical inviscid membrane airfoil theory and with a portion of the available experimental data for membrane wings. The results indicate that classical potential-based membrane airfoil theory can provide a meaningful description of membrane wing aerodynamics only for a small range of incidence angles near ideal and then only for membrane airfoils with small excess length ratios. For larger excess lengths and incidence angles viscous effects dominate the aerodynamics. The agreement of the computed results with the experimental data is mixed. The current status of the available experimental data for membrane airfoils is also reviewed.