Aerodynamic performance computations for an S809 airfoil with aileron controls^for horizontal-axis wind turbine

摘要

The flow about an S809 airfoil with 40 percent chord unvented and vented aileron control surfaces was investigated with the incompressible and compressible Navier-Stokes equations. ^All computations presented in this paper are for fully turbulent flow and were conducted with the one-equation turbulence models of Baldwin-Barth and Spalart-Allmaras. ^Flow conditions included Mach number of 0.10, Reynolds number of 1 million based on airfoil chord and angles of attack of 12, 18, 27, 35, and 45 deg. ^Control deflections for this study were -57 deg, -87 deg for the unvented aileron, and -60 deg, -90 deg for the vented aileron. ^For the angles of attack and control deflections selected, the flow about the airfoil and control surfaces was unsteady with extensive regions of flow separation. ^Computed force, moment and pressure coefficients were compared with available wind tunnel data. ^In many cases, the magnitudes of the computed aerodynamic coefficients did not correlate well with the experimental results. ^Strouhal number computations were found to be within the experimentally established range for bluff bodies. ^(Author)