[sm0226]

Hi. I`m new in openFoam. Just started learning about snappyHexMesh.

in snappyHexMeshDict, what does this number(4 0 10) mean??

gapLevel (4 0 10)

I think, the first number is the cell number between two surfaces. and last one is refinement level. That`s right??

[Светлана]

Hi sm0226

I didn't use this feature before, but a quick search shows this:

"The specification is enabled by using the gapLevel keyword in a refinementRegion (in the refinementRegions section in the snappyHexMeshDict dictionary) and consists of three integers:

• the number of cells in the gap
• minimum cell level at which to apply the detection and refinement, and
• maximum cell level at which to apply the detection and refinement"

https://www.openfoam.com/releases/op...0+/meshing.php

Regards,
Svetlana

[Owais Shabbir]

Hi,

To build on what Svetlana wrote..

I am using the gapLevel entity in my snappyHexMeshDict and it really helps when you have extremely narrow passages in your geometry and while having not very high refinement criteria defined in the castelled mesh section.

I will attached a picture(cross-section of my mesh) to show how it has helped.
I have two solid stls in my fluid domain. Yellow is 1 stl and red dots are 2nd stls.

The circle in green shows the narrow gap, it has in my case is 2 mm of gap bw two stls. Without gapLevel snappyHexMesh didnt produced mesh in that region, therefore no mesh was generated. but this is the result of using gapLevel.

I have chosen (2 0 2).
for simplicity, lets take your example of (4 0 10): takes every 4 cells throughout in the gap and apply refinement of min level 0 and max level of 10.
BR
Owais