High-order curvilinear hybrid mesh generation for CFD simulations
File(s)2018-aiaa-scitech.pdf (4.97 MB)
Accepted version
OA Location
Author(s)
Type
Conference Paper
Abstract
We describe a semi-structured method for the generation of high-order hybrid meshes suited for the simulation of high Reynolds number flows. This is achieved through the use of highly stretched elements in the viscous boundary layers near the wall surfaces. CADfix is used to first repair any possible defects in the CAD geometry and then generate a medial object based decomposition of the domain that wraps the wall boundaries with partitions suitable for the generation of either prismatic or hexahedral elements. The latter is a novel distinctive feature of the method that permits to obtain well-shaped hexahedral meshes at corners or junctions in the boundary layer. The medial object approach allows greater control on the “thickness” of the boundary-layer mesh than is generally achievable with advancing layer techniques. CADfix subsequently generates a hybrid straight-sided mesh of prismatic and hexahedral elements in the near-field region modelling the boundary layer, and tetrahedral elements in the far-field region covering the rest of the domain. The mesh in the near-field region provides a framework that facilitates the generation, via an isoparametric technique, of layers of highly stretched elements with a distribution of points in the direction normal to the wall tailored to efficiently and accurately capture the flow in the boundary layer. The final step is the generation of a high-order mesh using NekMesh, a high-order mesh generator within the Nektar++ framework. NekMesh uses the CADfix API as a geometry engine that handles all the geometrical queries to the CAD geometry required during the high-order mesh generation process. We will describe in some detail the methodology using a simple geometry, a NACA wing tip, for illustrative purposes. Finally, we will present two examples of application to reasonably complex geometries proposed by NASA as CFD validation cases: the Common Research Model and the Rotor 67.
Date Issued
2018-01-01
Date Acceptance
2017-08-31
Citation
AIAA Aerospace Sciences Meeting, 2018, 2018, (210059)
ISBN
9781624105241
Journal / Book Title
AIAA Aerospace Sciences Meeting, 2018
Issue
210059
Copyright Statement
©2018 AIAA. All rights reserved.
Sponsor
Commission of the European Communities
Identifier
https://arc.aiaa.org/doi/abs/10.2514/6.2018-1403
Grant Number
675008
Source
AIAA Aerospace Sciences Meeting
Subjects
cs.GR
cs.GR
cs.CG
physics.comp-ph
physics.flu-dyn
Publication Status
Published
Start Date
2018-01-08
Finish Date
2018-01-12
Coverage Spatial
Kissimmee, FL, USA