Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Interpolation curve impact in a freeform wing optimization
Submission Author:
Diego Bandeira de Melo Akel Thomaz , AM
Co-Authors:
Diego Bandeira de Melo Akel Thomaz, Pedro Tiago, Renata Onety, Thiago Pontin Tancredi
Presenter: Diego Bandeira de Melo Akel Thomaz
doi://10.26678/ABCM.COBEM2021.COB2021-1550
Abstract
Wing optimization is a topic extensively discussed in the literature of Aerospace Engineering and can be an important resource during the design processes. Usually, once the requirements have been defined, the aircraft design starts with aerodynamic phase. It is important to note that these results have great impact on several areas such as control and stability, structures and aeroelasticity. There are two traditional approaches for the wing optimization process: a parametric and a freeform optimization. Since high-precision performance evaluation is a time-consuming process, a freeform optimization using a RANS/DNS CFD code is tough. Thus, a good initial solution is an important requirement in this case, especially when adjunct technique is used. To help in this scenario, this work presents a wing optimization model that uses three sections to describe the shape of the wing. The section shape and attack angle are defined in a preliminary phase and are not investigated in this paper. Each wing section has three variables: offset, chord length and partial wingspan. The last variable considered is the chord length in the fuselage. The optimization objective is to maximize the wing lift. However, a runway length limitation required for takeoff limits the feasible design space. The forward swept wings are not allowed, and the total wingspan and wing taper are limited using data from literature. For the analysis, the Vortex Lattice Method was used with AVL (Athena Vortex Lattice) application. The optimization was done with an in-house code that uses an NSGA-II algorithm with random DOE. The main original contribution is the consideration of different interpolation curves used to define the shape of the wing. Three different interpolation curve models are used to define the sections between the three main sections. The first one is a linear interpolation that defines a straight wing shape. The other models use second and third degree equations, which result in organic shapes. The results showed that a high-order interpolation curve results in better performance without increasing the time consumed and will provide a better initial solution for a high-order CFD optimization process. Finally, the manufacturing and structural aspects are not considered.
Keywords
Aerodynamics, Optimization, interpolation
