💥💥💥 What are mesh quality and mesh errors in Ansys Fluent ?

 Mesh quality and mesh errors in Ansys Fluent are related to how well the mesh represents the geometry and the physics of the problem. A good mesh should have the following characteristics:

• It should conform to the shape of the domain and capture the important features of the geometry.
• It should have a smooth distribution of nodes and elements, without sudden changes in size or shape.
• It should have a low skewness and aspect ratio, which measure how far the elements deviate from an ideal shape (such as a square or an equilateral triangle).
• It should have enough resolution in regions where the flow is complex, such as boundary layers, shear layers, shock waves, etc.
• It should be compatible with the solver settings and the turbulence model used.

Mesh errors can occur when the mesh does not meet these criteria, and they can affect the accuracy and stability of the numerical solution. Some common mesh errors are:

• High skewness: This means that some elements are distorted or twisted, which can cause interpolation errors and convergence problems¹.
• Incorrect boundary layer meshing: This means that the mesh near the walls is not fine enough to resolve the viscous effects, which can lead to inaccurate predictions of wall shear stress and heat transfer¹.
• Coarse meshing: This means that the mesh is too coarse to capture the flow features, which can lead to numerical diffusion and loss of accuracy¹.
• A large aspect ratio leading to interpolation error: This means that some elements are stretched or compressed, which can cause errors in calculating the gradients and fluxes².

To check and improve the mesh quality in Ansys Fluent, there are several tools and methods available, such as:

• The Report Quality button in the General task page, which prints a message to the console with information about the mesh quality criteria¹.
• The Mesh Adaptation feature, which allows you to refine or coarsen the mesh based on various parameters, such as gradients, residuals, curvature, etc¹.
• The TUI commands or the Ansys Meshing tool, which allow you to modify or repair the mesh manually or automatically³.

How to check mesh errors and mesh quality in Ansys Fluent ?

There are several ways to check mesh errors and mesh quality in Ansys Fluent. Here are some of the resources that might help you:

• You can watch this YouTube video Ansys Fluent Tutorial - Check mesh quality errors and define mesh adaptation that shows how to use the Fluent interface to check and improve the mesh quality.
• You can also read this forum post When I open fluent and do mesh quality check, I’m that discusses a common warning message and how to fix it using the TUI commands or the Ansys Meshing tool.
• You can refer to this user’s guide ANSYS FLUENT 12.0 User’s Guide - 6.2.2 Mesh Quality that explains how to use the Report Quality button in the General task page and what the output means.