Aerodynamic scale effects on a transport-aircraft model at high subsonic speed

Abstract

A collaborative investigation has been performed within the Association of European Research Establishments in Aeronautics (AEREA) concerned with the study of aerodynamic scale effects on a transport-aircraft, wing-body model at high subsonic speeds. The model is representative of the DLR-F4 wing-body and has been tested in the cryogenic European Transonic Wind tunnel (Cologne) at high subsonic speeds and over a wide range of Reynolds numbers. An analysis of data, illustrating the effect of Reynolds number on overall forces and the simulations of high Reynolds-number flows at low Reynolds number, by the use of aft-located transition trips, is presented, with the following aims: To provide insight into the effects of Reynolds number on the aerodynamic forces on a wind tunnel model transport aircraft over a wide range of Reynolds numbers. To provide information on the effects of transition trips used in sub-scale wind tunnel testing (including trip roughness) and of the scope for simulation of ‘full-scale’ flows by adapting the transition trip position at low Reynolds numbers. . To obtain sufficient information to evaluate and analyse the observed Reynolds number effects (e.g. distinguish pseudo Reynolds-number effects such as model deformation, wall-interference and tunnel calibration effects).