Comparison of Constrained Parameterisation Strategies for Aerodynamic Optimisation of Morphing Leading Edge Airfoil

Andrea Magrini,Chen Wang,Volker Landersheim,Ernesto Benini,Conchin Contell Asins,Dominik Laveuve,Hamed Khodaparast,Michael Friswell,Rita Ponza

doi:10.3390/aerospace6030031

Abstract

In the context of ambitious targets for reducing environmental impact in the aviation sector, dictated by international institutions, morphing aircraft are expected to have potential for achieving the required efficiency increases. However, there are still open issues related to the design and implementation of deformable structures. In this paper, we compare three constrained parameterisation strategies for the aerodynamic design of a morphing leading edge, representing a potential substitute for traditional high-lift systems. In order to facilitate the structural design and promote the feasibility of solutions, we solve a multi-objective optimisation problem, including constraints on axial and bending strain introduced by morphing. A parameterisation method, inherently producing constant arc length curves, is employed in three variants, representing different morphing strategies which provide an increasing level of deformability, by allowing the lower edge of the flexible skin to slide and the gap formed with the fixed spar to be closed by a hatch. The results for the optimisation of a baseline airfoil show that the geometric constraints are effectively handled in the optimisation and the solutions are smooth, with a continuous variation along the Pareto frontier. The larger shape modification allowed by more flexible parameterisation variants enables an increase of the maximum lift coefficient up to 8.35%, and efficiency at 70% of stall incidence up to 4.26%.

Highlights

In the frame of increasingly stringent regulations governing the air transport sector [1], driven by environmental and economic concerns, continuing efforts are being made to reduce air traffic fuel consumption, pollutants, and noise emissions
Morphing is recognised as a technology with the potential of an effective improvement of flight efficiency by continuous adaptation of wing shape to external conditions
The scope of this paper is to investigate suitable methods for the aerodynamic design of a morphing leading edge, by employing a constrained shape parameterisation for the aerodynamic optimisation, including structural constraints to limit the stress induced by the deformation

Summary

Introduction

In the frame of increasingly stringent regulations governing the air transport sector [1], driven by environmental and economic concerns, continuing efforts are being made to reduce air traffic fuel consumption, pollutants, and noise emissions. 2050 [2], international institutions set ambitious targets. This encourages aircraft manufacturers to develop innovative solutions for future vehicles, looking at novel configurations and technologies. Morphing is recognised as a technology with the potential of an effective improvement of flight efficiency by continuous adaptation of wing shape to external conditions. It can involve a change of the wing section, wing plane, or an out-of-plane deformation [3], but a general classification has still to be agreed upon [4]

Objectives

Results

Conclusion