Aerodynamic Shape Optimization of Highly Nonplanar Raised and Drooped Wings

Abstract

Aircraft wings are commonly designed with non-planar geometry, such as winglets, in order to improve aerodynamic efficiency. This work presents a method for generating nonplanar wing designs through gradient-based optimization, which is then used to investigate the performance characteristics of non-planar wings. The non-planar parameterization is defined to give a large design space that allows the formation of highly non-planar features and permits large changes to the geometry. Aerodynamic characteristics are captured using an inviscid 3D panel method with approximations for viscous drag. The methodology is demonstrated by optimizing reference wings from literature and comparing aerodynamic performance. Investigations are also performed on the impact on performance when wings are raised or drooped, and the differences in aerodynamic behavior between the two designs.

Investigating Planar and Nonplanar Wing Planform Optimisation for Ground Effect Aircraft

“…It is important to note that ground effect is a three-dimensional phenomenon, hence its benefits cannot be fully explored through two-dimensional airfoil optimisation alone. Nonplanar wings have been shown to reduce the induced drag beyond planar wings [13,14]. However, only few examples are available in the literature to better understand whether nonplanar wings could satisfy the stability requirements of WIG aircraft.…”

“…In a numerical optimisation study on winglets, Ning and Kroo [22] employed a vortex-lattice method to calculate induced drag while assuming a parabolic relationship between viscous drag and lift. Smith et al [23] applied panel methods for optimising wing planforms by minimizing the induced drag and then extended the approach to incorporate non-planar variations in the design space and coupled it with XFOIL for viscous drag computation [14]. Recently, Salem et al [24] employed a VLM method to include ground effect aerodynamics in the assessment of take-off considerations within the conceptual design of box-wing aircraft.…”