Aerodynamic Design of a Nacelle for Aeroelastic Wind Tunnel Experiments in Transonic Flow.

Abstract

The Institute of Aeroelasticity plans a series of experiments on a wing-nacelle configuration in order to study interference effects on unsteady aerodynamics and transonic flutter. For this purpose, a trough-flow nacelle was designed aerodynamically. Its large diameter/length ratio (design goal D/L&#610.7) should count for future developments of high-bypass-ratio engines. The design process of the clean nacelle was performed for subsonic (Ma&#610.6) and transonic Mach numbers (Ma&#610.8) using different numerical methods (3d Euler calcula-tions, 2d Euler/boundary-layer calculations and 3d Navier-Stokes calculations). Most of the design goals such as avoiding large separation, one clearly defined supersonic region for Ma>0.7 and no blockage inside the nacelle could be achieved.