Pre-Computations for the iGREEN Wing-Tailplane Interference Experiment in the TWG

Abstract

This report summarises a numerical investigation of a wing-tailplane interference configuration for testing at transonic Mach numbers in the DNW-TWG. In the configuration investigated, a 2D airfoil with the NLR7301 profile was mounted upstream of the swept, tapered Aerostabil wing. The wing-tailplane interference effect generated by this geometry and the effect of the wind tunnel side-wall boundary layer on the models was investigated. It was found that the side-wall interference effect on a 2D airfoil is amplified by the formation of separations in the corners between the wall and the airfoil. This causes the airfoil to have changes in the pressure distribution, similar to if it were at a lower angle of attack than expected by assuming that the airfoil is truly 2D. The computations on the Aerostabil wing showed that the side-wall interference effect and the wing-tailplane interference effect are of the same order of magnitude, with the ratio between the two effects not changing significantly with Mach number. Increasing the angle of attack of the NLR7301 increases the wing-tailplane effect relative to the side wall effect. It is clear that choosing test conditions in which the two effects can be separated will be important for experimenters on this configuration.