Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
High order boundary treatment for high order methods in computational fluid dynamics
Submission Author:
André Ribeiro de Barros Aguiar , SP
Co-Authors:
Carlos Breviglieri, Fábio Malacco Moreira, Eduardo Jourdan, João Luiz F. Azevedo
Presenter: André Ribeiro de Barros Aguiar
doi://10.26678/ABCM.ENCIT2016.CIT2016-0219
Abstract
A relatively new class of numerical methods is currently under development by the Computational Fluid Dynamics (CFD) community. These methods are known as high-order methods and their main property is to obtain a higher convergence rate when compared to their low-order counterparts. A more subtle implication of that relies on the fact that one may reach the same error as that obtained with low-order schemes by using relatively less computational effort. When dealing with these high-order numerical schemes in CFD, however, a meaningful accurate solution can only be obtained if a corresponding high-order approximation of curved boundaries of the geometry is employed. Inaccurate and even unstable solutions arise from geometry represented by straight faces as opposed to curved ones. In the current state of the art, curved mesh generators are not readily available since high-order schemes are still under development. The current work will be concerned with the main issues and benefits related to the use of a curved boundary treatment for high-order methods. A complete methodology to project nodes from an original linear unstructured 2-D mesh into a new curved mesh will be detailed and its effectiveness will later be assessed using a high-order Spectral Difference scheme on standard test cases. The methodology applied handles the complete description of a 2-D geometry as represented by a Non-Uniform Rational B-Spline (NURBS) curve entity. The validation of the results will be carried out using a subsonic flow over a 2-D cylinder where the issues of using straight sided meshes will be highlighted. The resulting framework will also be applied to flows over NACA 0012 airfoil configuration and a RAE supercritical airfoil.
Keywords
high-order boundaries, Spectral difference methods, High-order methods, CFD
