Having problems implementing a hex mesh with inflation

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  • Last Post 03 January 2020
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rachels1001 posted this 12 December 2019

Hey guys,

I am having an issue with creating a hex mesh for this geometry.

My problem is that I also have to include inflation layers at the walls of the central body. Hex dominant methods are not compatible with inflation, and when I've been trying to implement a multi-zone mesh, it tells me that the meshing is failing. I've enabled free mesh type in the multi-zone mesh.

I feel like I probably need to slice the central geometry to implement the multi-zone mesh, but I'm a little confused about how I should slice it and how to select the source faces?

I've gone over the multizone mesh pages on Ansys help, any help is appreciated!

Thanks,

Claire

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peteroznewman posted this 13 December 2019

Hey Claire,

Never, ever use Hex dominant mesh methods on a CFD mesh.  It says so in the ANSYS Help system.

This method gives horrible elements in the center of the volume, which a Mechanical Solver does not care about but which ruins CFD solutions.

Yes, you should slice the geometry into six-sided bodies. These can then be meshed with Sweep method. With sweep method, you can bias the elements along the sweep to create "inflation" layers without using the Inflation mesh control.  Maybe you will be sweeping parallel to the flow, then two edges of the source face can have bias to create the "inflation" layers.

Regards,
Peter

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Manel40 posted this 31 December 2019

Hi Peter; 

 

I don't see why  Cvelikonja must slice his or here geometry to apply Sweep method ? What should happen if sweep method is applied without slicing 

geometry ? 

Thanks you very much for response

Best regards ,

Manel

 

 

peteroznewman posted this 31 December 2019

Hi Manel,

Sweep only works on six-faced bodies. If you apply a sweep method on a body with more that six faces, it will fail and the mesher will use the default method instead.

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Manel40 posted this 03 January 2020

Ok thanks you a lot

rwoolhou posted this 03 January 2020

Just to add, we've had good success using an inflated poly mesh for cyclones. Make sure to pick the correct turbulence model too! 

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