Global Aerostructural Design Optimization of More Flexible Wings for Commercial Aircraft

Abstract

In the German Aerospace Center's Virtual Aircraft Technology Integration Platform project, a process for aerostructural wing optimization based on high-fidelity simulation methods is continuously developed. Based upon a parametric geometry, flight performance under transonic flight conditions and maneuver loads are computed by solving the Reynolds-averaged Navier-Stokes equations. Structural mass and elastic characteristics of the wing are determined from structural sizing of the composite wing box for essential maneuver load cases using computational structural mechanics. Global aerostructural wing optimizations are performed for wings with a conventional composite wing-box structure and for more flexible wings. The minimization of the fuel consumption for three flight missions represents the objective function. The optimizations are performed for variable and constant wing planforms as well as with and without consideration of active maneuver load alleviation. A significant mass reduction of the wing box is obtained with the more flexible wing concept, resulting in a decrease in fuel consumption of about 3%. For the optimizations with active maneuver load alleviation, the more flexible wing concept shows an additional reduction of the fuel consumption on the order of 2%. The more flexible wing concept results in optimized wing geometries with increased aspect ratios and reduced taper ratios.