Is there a way to force the mesher to have a mimmium edge length outside a geometry primitive?‘’
I feel like alot of cells are wasted in refinement of the empty regions in the corners of the flow region.
Or is there a way I can make the simulation more efficeint? Each sim currently costs around 100 core hours
I’m using the hex dominant mesher with fine meshing,
Thanks in advance for any help!
Project link is here
Thank you for posting on the forum and sharing your project!
We will go through the project and get back to you soon
Can you tell me why are you using hex dominant mesher as opposed to the standard algorithm mesher? It’d be helpful to know this in order to proceed
Using the standard mesher gives you almost the same quality mesh with any refinements and takes up only a few core hours.
I’m sure the mesh quality can be improved by adding refinements in the geometry primitive regions as well.
You have to use the Hex-Dominant Parametric meshing algorithm.
What I recommend is that you set your Background Mesh Box (BMB) sizing to integer values in meters.
Then you set the Bounding Box Resolution in the HexDomPara parameters to the number of meters your BMB is in each direction.
Now, all your mesh refinements will have cell sizes for their levels that will start at Level 0 is 1m, Level 1 is 0.5m and so on down in a binary progression.
I find this helps greatly because you can make your BMB quite large to reduce BMB wall interactions at very small cell count penalty.
Here is a current project which uses that process:
LazairFoil by DaleKramer | SimScale
I am not saying the the Standard mesher does not have any value as it is simple to use but I personally still have concerns about the precise accuracy of using TET cells for CFD based projects AND I did answer your exact topic query
The standard mesher is very inefficeint at preserving the geometry at high fineness, these are supposed to be vortex generators but they got mangled by the mesher
I might add a region refinement there
Would the mesh settings for the Foil project you posted work for a larger scale simulation? I have to simulate a vehicle around 5mx1.8mx1m and its pretty difficult getting good meshes
Yes absolutely, 1m level 0 is great even for large aircraft.
You will be able to precisely mesh you vortex generators too
I have never needed past Level 11.
Here are a couple great links that could help you:
Starting at the foundation of a problem free simulation is having the correct CAD geometry. This fact cannot be overstated enough as this has been proven time and time again over the course of testing. Therefore, there are two main concepts that must be understood.
Having a correct CAD Geometry has a HUGE IMPACT on the resulting mesh quality. If not prepared correctly, the mesh could possibly fail.
A good mesh will result in an accurate simulation. In addition, a bad me…
This will be a two part Article as the second half (Y+ Validation) is still not complete and will be added later.
Boundary Inflation Techniques
A critical part of any CFD simulation is having the correct Y+ value. The target value is determined based on the type of flow you are trying to measure. When it is desired to measure wall shear force or accurate flow separation points, then full resolution of the viscous sub-layer is required using a Y+ value less than 8. However,…