CFD with no meshing… where’s the catch?
Posted by Rob Kaczmarek on July 11, 2013
Every CFD engineer in the world today has experienced the pain of meshing. The endless hours of trying to get a mesh to work with a particular complex geometry, trying to decide between structured and unstructured, deciding where to put mesh resolution, etc. With recent advancements meshing may be as outdated as your old Commodore 64.
Not the mesh itself, but the process of creating a user defined mesh.
With recent advancements in commercial CFD codes the ability to automate the meshing process is becoming more and more prevalent. We’ve assembled the Top 5 features to look for when evaluating a product that claims to have automated meshing.
5 Important Features of Automated Meshing
1. Method Used. When looking for a CFD tool with automated meshing it’s important to look for the tool that automates at run-time, for each time step, with a stationary, orthogonal, structured mesh. This will reduce inaccuracies from numerical diffusion due to a deforming mesh for moving boundary applications. The Cartesian cut-cell approach overcomes many of the limitations of the immersed boundary method and is therefore preferred.
2. Complex Moving Geometries. The ability to handle complex geometries is a must and the automated mesher must be robust enough to handle any geometry, moving or non-moving.
3. Mesh Refinement. The ability to refine the mesh on the fly, at run-time, based on gradients is key. This will produce the best results with the least amount of computational expense by placing mesh elements when and where they are most needed. Fixed embedding is also a nice feature to have when you know exactly where the added mesh will be needed.
4. Exact Geometric Representation. Having the true representation of your model will offer you the advantage of an exact geometric representation independent of the mesh size. This offers numerous benefits including the ability to apply more cells near a wall and get an increase in accuracy, and running a fast coarse mesh without distorting the geometric representation.
5. Running in parallel. Meshing in parallel is essential to getting a timely CFD analysis. Without the mesh being created in parallel you run the risk of adding hours to your run times.