Numerical Investigation of Wing-Nacelle Interference Effects at Transonic Flow Conditions for a Generic Transport Aircraft Configuration

Abstract

A detailed numerical and experimental investigation of the steady/unsteady wing-pylon-nacelle interference effects on flutter characteristics has been initiated between DLR and ONERA. This paper presents prelimary numerical simulation results of steady flow phenomena occurring in the engine region of a generic aircraft configuration. Main issues of this project phase are parameter investigation and definition of a wind-tunnel model geometry which is used for the forthcoming experimental measurements. Several geometry and flow parameters are varied and their influence on interference phenomena is investigated in order to design the final model geometry which satisfies given wind-tunnel and production constraints. Results show that, for the development and strength of interference effects, the nacelle yaw angle and the wing-nacelle overlapping parameters play the crucial role while the effect of wing sweep angle parameter is similar to that of nacelle yaw angle. Thus interference effects of a swept wing-nacelle configuration can be simulated by a rectangular wing with nacelle and pylon yaw degree of freedom.