On Mesh Convergence and Accuracy Behaviour for CFD Applications

• Main Author: Elraghy, Abdalla
• Other Authors: Zingg, David W.
• Language: en_ca
• Published: 2013
• Subjects: engineering; aerospace; mesh; topology; aeronautical; aircraft; aerofoil; convergence; accuracy; adjoint method; 0538
• Online Access: http://hdl.handle.net/1807/35603

Computational Fluid Dynamics (CFD) is a main field that contributes to the development of high efficiency aircraft. CFD accuracy depends on the flow solver and the meshing of the geometry, and while it is doable to determine why a certain solver is more accurate than another, it is much more difficult to discern why two meshes produce differently accurate solutions. A framework is presented to evaluate the performance or ``goodness" of a mesh and to compare meshes. The framework is composed of quantifiable mesh parameters which define a mesh, and three performance measures: functional accuracy, their order of convergence, and their behaviour under the adjoint correction method. Although it seems that the relationships between parameters and results are not trivial, there are trends from which optimal mesh parameters are deduced. The H topology performs best, and the most important parameters are related to spacings and cell quality around the aerofoil leading edge.