Meshing a very narrow gap

  • Last Post 09 October 2018
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ekasakharova posted this 14 September 2018

Hello everyone,

I am trying to mesh a model which has a significant size jump in its geometry. Unfortunately, with no success.

Let my try to explain what I mean: there's a model of a colloid mill which works on a rotor-stator principle. Also, there is an extremely small shear gap (0.09 mm) between rotor and stator. The model I try to mesh is the fluid which fills the colloid mill; this narrow gap is also filled.

I have no problems with meshing the whole model except for the gap: Ansys Meshing has big issues in that region. Currently my assembly contains two bodies: rotor and stator with a cut made in the middle of the gap, which means each gap half belongs either to rotor or stator.

The only solution I have found is to slice this gap from the rotor-stator system and somehow mesh it separately, in other words: I will have stator, a part of the gap which belongs to stator, a part of the gap which belongs to rotor, and rotor. Please note, here I am talking about the fluid model, the one I need to put a mesh on. Also, I need to have at least 10 elements in each gap half.

My question is: is there another possible and preferably an easy way to do it?

Thank you in advance!



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rwoolhou posted this 14 September 2018

There are a few easy ways of doing this. 

The best approach is probably to break  off (decompose) the thin volume(s) so you can sweep mesh them first, and then tet the rest: look up sweep in Help. Note you will still have a fairly high cell count but it'll be manageable. 

The easiest approach is to decrease your minimum cell size until you can get 5-10 cells in the gap using the proximity size function. This may give a huge mesh, but it is easy! 

You then create two multibody parts (DesignModeler) or componenents (SpaceClaim) to get a conformal mesh where you want it. 

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ekasakharova posted this 27 September 2018


thank you so much It's solved!

I have one more question: is it possible to merge multiple mesh files in Meshing mode of Ansys? I have now three different meshes and want to merge them into one. Unfortunately Meshing User's Guide wasn't helpful here...



Aniket posted this 05 October 2018

you can assemble multiple mesh files as shown in the image below:

Note that you can connect mesh/model cell of multiple systems to mesh/model of an assembly system.


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rwoolhou posted this 09 October 2018

Or in Fluent you can also read in a Mesh file and then append additional meshes as needed. It's an older trick for back when we didn't have all of the nice GUI driven tools and wanted (for the time) big meshes.