[snappyHexMesh] Average cell size

emma · October 24, 2022, 12:45

Hi,

I have to do a grid convergence study and i need the average cell size (mesh obtained with snappyhexmesh), but i can't figure it out how to do it.
Could someone help me?

Thanks

AtoHM · October 25, 2022, 03:28

1) checkMesh can put out cellVolume field which you can use (-writeAllFields option)

2) Paraview has a filter called mesh quality. This allows you to extract all sorts of quality measures per cell. You can presribe it to put out the cell volume as a field, which you can either export and process somewhere else or make e.g. a histogram in Paraview itself. I remember with this approach, sometimes PV is not able to extract volume (or was it area?) correctly for all cell types, then the result may be off.

MohdShaeq · May 13, 2024, 08:55

Quote:

Originally Posted by emma

Hi,

I have to do a grid convergence study and i need the average cell size (mesh obtained with snappyhexmesh), but i can't figure it out how to do it.
Could someone help me?

Thanks

The average element/cell size can easily be calculated by the following formula:-

$^{E}size$ = $\sqrt[3]{^{V}mesh/^{N}hex}$
where
$^{E}size$ is the average size of an element,
$^{V}mesh$ is the volume of the mesh, and
$^{N}hex$ is the number of hexahedral elements of which the mesh is composed.

The latter two can easily be found out using the checkMesh utility.

The following link explains this procedure in detail:-
https://www.sandia.gov/files/cubit/1...tem/set-up.htm

October 24, 2022, 12:45	Average cell size	#1
emma New Member Join Date: Oct 2022 Posts: 1 Rep Power: 0	Hi, I have to do a grid convergence study and i need the average cell size (mesh obtained with snappyhexmesh), but i can't figure it out how to do it. Could someone help me? Thanks

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
UDF in case with DPM modle	POSTHU	Fluent UDF and Scheme Programming	0	March 3, 2021 08:21
Choice of cell size w.r.t size of the domain for meshing	mazhar16823	Main CFD Forum	1	June 16, 2020 02:53
[mesh manipulation] How to write cellSet for different regions in constant/polyMesh/sets	Struggle_Achieve	OpenFOAM Meshing & Mesh Conversion	3	June 17, 2019 10:29
Courant Number Cell Size	vitorgabriel	OpenFOAM Pre-Processing	0	June 3, 2016 11:41
OF 1.6 \| Ubuntu 9.10 (64bit) \| GLIBCXX_3.4.11 not found	piprus	OpenFOAM Installation	22	February 25, 2010 14:43

October 25, 2022, 03:28		#2
AtoHM Senior Member M Join Date: Dec 2017 Posts: 703 Rep Power: 13	1) checkMesh can put out cellVolume field which you can use (-writeAllFields option) 2) Paraview has a filter called mesh quality. This allows you to extract all sorts of quality measures per cell. You can presribe it to put out the cell volume as a field, which you can either export and process somewhere else or make e.g. a histogram in Paraview itself. I remember with this approach, sometimes PV is not able to extract volume (or was it area?) correctly for all cell types, then the result may be off.