Glider fuselage-wing junction optimization using CFD and RBF mesh morphing

Abstract

Purpose - The present paper aims to address the description of a numerical optimization procedure, based on mesh morphing, and its application for the improvement of the aerodynamic performance of an industrial glider which suffers of a large separation occurring in the wing-fuselage junction region at high incidence angles. Design/methodology/approach - Shape variations were applied to the baseline configuration through a mesh morphing technique founded on the mathematical framework of radial basis functions (RBF). The aerodynamic solutions were obtained coupling an RANS code with the mesh morphing tool RBF Morph™. Two shape modifiers were set up to generate a parametric numerical model. An optimization procedure, based on a design of experiment sampling, was set up implementing the fully automated workflow within a high performance computing (HPC) environment. The optimal candidates maximizing the aerodynamic efficiency were identified by means of a cubic RBF response surface approach. Findings - The separation was significantly reduced, modifying the local geometry of fuselage and fairing and maintaining the wing aerofoil unchanged. A relevant aerodynamic efficiency improvement was finally gained. Practical implications - The developed procedure proved to be a very powerful and efficient tool in facing aerodynamic design problems. However, it might be computationally very expensive if a large number of design variables are adopted and, in those cases, the method can be suitably used only within the HPC environment. Originality/value - Such an optimization study is part of an explorative set of analyses that focused on better addressing the numerical strategies to be used in the development of the EU FP7 Project RBF4AERO

Combining Analytical Models and Mesh Morphing Based Optimization Techniques for the Design of Flying Multihulls Appendages

“…The separation observed adopting the fine grid, causing the performance reduction, is generated as interference between the hull wall and the foil and is a typical occurrence in aircraft design when dealing with wall junctions. The impact of the flow separation can be reduced by an approach based on local shape modification as shown in a similar case in (Biancolini, et al, 2016) where an improvement of about 35% in efficiency was achieved on a manoeuvring glider experiencing flow separation in the wing-fuselage junction area.…”

Fast interactive CFD evaluation of hemodynamics assisted by RBF mesh morphing and reduced order models: the case of aTAA modelling

“…Notable examples of RBF applications are fluid-dynamic and structural shape optimizations [14,35], fluid structure interaction [3,8], and motorsport [45], nautical [13,50], road infrastructures [48] and medical [9] analyses.…”

A balanced load mapping method based on radial basis functions and fuzzy sets

“…As already introduced in Section 1, RBF applications recur in many different areas of science and engineering: neural networks in computer graphics (surface reconstruction), solution of partial differential equations, and mesh morphing in image analysis of deformations . RBF mesh morphing has been used for several applications, from FSI coupling to genetic and evolutionary optimizations and advanced modeling …”