[ebah6]

Hello everybody,

I am starting with openfoam and went through some tutorials.
Now I want to start a case of my own.
Basically, what I am doing is to copy one of the tutorial cases and modify it.

In the boundary file in case/constant/polyMesh/boundary, there are numbers that goes along with the nFaces and startFace.
Can someone help me know what they correspond to and how to choose accordingly in my case?

Thank you for your help.

Alpha

[wiedangel]

Hi Ebah,

to create a mesh in OpenFoam you need to use blockMesh (this can be done by modifying the blockMesh file which is to be saved in the constant/polyMesh directory) or by using snappyHexMesh.
If you are copying a case directly from the tutorials and the mesh was generated by blockMesh (like the cavity case) you can modify the blockMesh dictionary to modify the mesh you have. You can check the tutorial which is here for more informations about blockMesh:
http://www.openfoam.org/docs/user/blockMesh.php
this will give you some hints on how blockMesh works.

I hope it will help.

[ebah6]

Thanks for the reply.

I get how to modify to blockMeshDict file. My question was referring to the boundary file where you can find some thing like this:

inlet
{
type patch;
nFaces 50;
startFace 11210;
}

In these line how one determines what number to put in front of NFaces and/or startFace.
Here these numbers are 50 and 11210 respectively; but they change according to the case. How to choose them properly?

Thanks for consideration.

[wiedangel]

you don´t have to write these by yourself, blockmesh does it for you. If you are using icem to generate your mesh you get these files when you convert them to openfoam format.