Experimental Validation of Pressure Distribution Prediction under Delta Wing Apex Vortex at High Reynolds Numbers

Abstract

This study presents an application of the Fluent CFD methodology to solve Navier-Stokes equations, for the forecast of flow implying evolution of principal vortices developed on suction face of a thin delta wing. A delta wing model with apex angle ?=80° is subjected to measurements in subsonic wind tunnel and defect pressure coefficient values reached under the apex vortex core are obtained via a row of pressure taps. Numerical simulations are carried out for the same experimental delta wing model at angle of attack i=15°, before the vortex bursting, and at Reynolds number based on the wing chord Re=1.0840×105. Numerical predictions of defect pressure coefficient –Cp are compared to experimental data. Good agreement is obtained between predictions and measurements. Pressure and velocity evolutions at different cross-sections of the longitudinal vortex were also considered allowed us to reveal clearly the apex vortex core. The numerical results analysis in several cross sections reveals a peak distinct under the principal apex vortex. At the studied delta wing suction face the defect pressure coefficient reaches maximal value close to 2.5 which agrees with that found in literature.