Aerostructural Optimization of Drooped Wings

Abstract

Through aerostructural optimization, this paper presents progress towards characterizing the potential e ciency gains of drooped wings for commercial aircraft in transonic flight. The drooped wing is a nonplanar configuration with downward spanwise camber from the wing root to the tip. The aerostructural optimization cases include two load conditions: cruise and 2.5g. The single 2.5g maneuver load condition is used for structural sizing of the wing. In all cases, the projected span of the wing remains unchanged. The results show that such a wing has the potential to improve aircraft range by 2.6% relative to an optimized planar wing of the same projected span. The reason is that the drooped wing pushes the tip vortex further away than the planar wing and increases the projected span at the deflected state. Furthermore, if the drooped wing is permitted to have curved leading and trailing edges, a 4.9% range improvement in comparison to an optimized planar wing with straight leading and trailing edges is possible by further reducing wing weight and wave drag.

Aerodynamic Shape Optimization of Highly Nonplanar Raised and Drooped Wings

“…Consider the optimization problem in (17), with the objective to maximize e, and an upper constraint on the wingtip value of q. Here, only one design variable per section is included, x = δq, where a = 0, and c = b/AE R 0 to give a rectangular planform with an aspect ratio equal to that of previous studies.…”

“…From Table 2 one would assume that drooped wings are superior to raised wings as they can create a larger gain in efficiency. However, the optimization study in (17) has a restricted design space as only q was allowed to change and the chord distribution was fixed. In most practical designs the wing will taper towards the tip, which in the case for raised wings would alleviate some the increased drag experienced towards the tip in Fig.…”

“…The drooped wing designs here are again motivated by seagull wings in gliding flight. Khosravi and Zingg [17] conducted aeroelastic optimization studies of drooped wings which produce efficiency gains of up to 5% compared to optimized planar wings.…”

Parametric Surfaces with Volume of Solid Control for Optimisation of Three Dimensional Aerodynamic Topologies

“…Drag minimisations of wings are common cases within the aerodynamic shape optimisation community [42,43]. Figure 9 presents a coarse representation of a wing using a [2,5,6] layout of design variables.…”

Aerostructural Design Exploration of a Wing in Transonic Flow

“…One of the first high-fidelity aerostructural optimizations was conducted by Martins et al [13], who optimized the wing shape and wingbox sizing of a supersonic business jet using Euler computational fluid dynamics (CFD) and a finite-element model. Since then, there have been various other efforts using CFD-based aerostructural optimization with both Euler [14,15] and Reynolds-averaged Navier-Stokes (RANS) models [16][17][18][19][20]. Although more accurate fluid flow models are possible with large-eddy and direct-numerical simulations, the computational cost of such methods renders them prohibitive for wing design optimization with the current technology.…”