Numerical airfoil catalogue including 360° airfoil polars and aeroacoustic footprints

Kurzfassung

A methodology is presented for generating 360° airfoil polars and aeroacoustic characteristics by means of CFD and CAA. The aerodynamic procedure is validated against experimental data of the well-known airfoils DU-93-W-210 and DU-97-W-300. While a better prediction of the aerodynamic coefficients in the range of -30° and 30° is achieved by a combination of the k-w SST turbulence model and a C-topology mesh, for the remaining angles of attack more confidence is gained with the SA negative turbulence model in combination with an O-topology mesh. Therefore the two data sets are subsequently fused to one complete data set using a kriging interpolation approach. The result of ten different airfoils using the proposed method is presented. For providing the aeroacoustic characteristics for a wide operation range four computations and a bilinear interpolation are needed, since the aeroacoustic is dependent on the Mach and Reynolds number. The bilinear interpolation approach is verificated by a comparison between the originally simulated and the emulated result at a fifth computational set for six different airfoils. The corresponding overall sound pressure level (OASPL) for four angles of attack for these airfoils is presented and the difference between a fully turbulent computation and simulations with fixed transition is assessed. The aeroacoustic results further include high-fidelity directivity functions.