Analysis of transonic aerodynamic interference in the wing-nacelle region for a generic transport aircraft

Abstract

This paper presents results of a numerical investigation dealing with steady and unsteady aerodynamic wing-nacelle-pylon (WNP) interference effects. In the first part of the paper the design process of the generic WIONA (Wing with Oscillating Nacelle) geometry is described. It is shown that development of major interference effects in the channel between wing and nacelle strongly depends on geometrical parameters of the configuration. After the geometry definition, the steady viscous interference effects are investigated and the influence of different flow parameters is analysed. It is shown that viscous interference features are dominated by the interaction between shoch wave and boundary layer. In the last part of the paper an analysis is given of the unsteady aerodynamic features for a WNP cluster. The unsteady aerodynamic response to the pitching oscillations is investigated and it is shown that local flow separation and reattachment play a crucial role in the possible aerodynamic excitation of the structure. Additionally, the issue of self sustained shock oscillation occurring in the WNP region in case of the stationary geometry (shock buffet) is investigated.