Overset Mesh

In this part of the tutorial we will mainly generate an overset mesh for ADflow. Here is a list of commonly used steps to create an overset mesh with the usual workflow in the MDO Lab:

1. Create the geometry using pyGeo, if necessary.

2. Generate surface meshes for the main components in ICEM.

3. Extrude surface meshes into volume meshes using pyHyp.

4. Generate a background mesh using cgnsUtilities.

5. Merge blocks in a single file using cgnsUtilities.

6. Check connectivities using ADflow.

We will take a slightly different approach in this tutorial by using OpenVSP to create the geometry and Pointwise to generate the surface meshes. The Aerodynamic Analysis tutorial covers how to use pyGeo and ICEM.

We will do this process on the ONERA M6 Wing, which is a common example to validate flow solvers in the transonic regime. Note that an overset mesh might not be needed for a simple geometry like this; however, we will use this geometry as an example to demonstrate the overset mesh surface overlap.

Here are a few of the items we will cover in the following pages:

• Some theory on overset meshes

• General tips and troubleshooting for overset meshes

• Create a wing geometry using OpenVSP

• Surface mesh generation with Pointwise

• Volume mesh extrusion with pyHyp

• ADflow analysis for overset meshes

Table of Contents

• Overset Theory
• Tips and Troubleshooting
• Geometry Generation
• Surface Mesh
• Volume Mesh
• CFD Analysis

About this tutorial

This tutorial was written by David Anderegg and Anil Yildirim. David Anderegg is employed by ZHAW in Switzerland at the time this tutorial was published. Most of the ‘Overset Theory’ and ‘Tips and Troubleshooting’ sections is based on material from Ney Secco.

References

[O1]

ONERA M6 Wing. URL: https://www.grc.nasa.gov/WWW/wind/valid/m6wing/m6wing.html.

[O2]

3D ONERA M6 Wing validation for turbulence model numerical analysis. URL: https://turbmodels.larc.nasa.gov/onerawingnumerics_val.html.

[O3]

3D ONERA M6 Wing validation for turbulence model numerical analysis - SA-neg model results. URL: https://turbmodels.larc.nasa.gov/onerawingnumerics_val_sa.html (visited on 2020-12-11).