Boundary layer calculations on the leeward surface of a slender delta wing at incidence

A 3D-boundary layer calculation method was used to predict the location of the secondary boundary layer separation on the leeward surface of a slender delta wing at incidence for fully laminar flow and forced boundary layer transition at the 50% semispan location. The behavior of the predicted boundary layer properties is qualitatively in good agreement with the experiment. A difference between the potential flow and experimental pressure distribution causes a discrepancy between the predicted and the experimentally observed location of secondary separation. It is expected that the potential flow pressure distribution can be improved when the leading edge and the secondary separation vortex sheet are correctly modeled in the potential flow calculation method. It is concluded that boundary layer calculations can provide valuable information for the location of the secondary separation line, to model the associated vortex sheet.