[Amirthaa]

This is my latest setup and you are right, the velocity is minimum for the geometry (and shows maximum for the domain).
By locationInMesh you mean insidePoint in SnappyHexMeshDict?

I have attached image of my view in paraView.

[Yann]

Yes, the locationInMesh parameter in snappy, which defines which part of the mesh is kept.

However, your screenshot is different from the mesh I got from the test case you uploaded in previous post. Please provide your latest setup and a script to run the case.

Yann

[Amirthaa]

Got it. But shouldn't the co.ordinates for it be a point inside the geometry?
Also, attaching here few directories created after my last run.

[Amirthaa]

Remaining file attachments:

[Amirthaa]

System directory:

[Yann]

Originally Posted by Amirthaa

Got it. But shouldn't the co.ordinates for it be a point inside the geometry?
Also, attaching here few directories created after my last run.

the coordinate should be in the volume you want to simulate.
If your geometry is a cube, and you want to simulate the flow around the cube, the coordinate should be outside the cube (but inside your mesh, usually defined by your blockMesh boundaries)
If you want to simulate the flow inside the cube, then yes the coordinates needs to be inside the cube. (so it's basically for internal flows)

Have a look at the user guide: https://www.openfoam.com/documentati...exmesh-utility

[Yann]

About the results you posted:

Your geometry is not meshed. You are running your solver on an empty mesh (it's basically only the mesh created by blockMesh).
You end up with a 10m/s flow in a domain without any obstacle.

Now, I think this is due to the fact you probably didn't use the overwrite option for snappyHexMesh. You can run snappyHexMesh -overwrite and it might solve the issue.

But this is only a guess since I have no idea of the commands you are using to run your case. This is why I asked for a script to run the case, so I can know what exact commands you are using. Without it it's not really possible to help you.

[Amirthaa]

You are right. Usage of snappyHexMesh -overwrite works. I have been able to get results. Thanks, Yann.

[Amirthaa]

Hello.
I have certain general doubts regarding OpenFOAM and ParaView which I haven't been able to find out clear answers for yet. It would be helpful if you are able to provide answers:
1) How to work and run files in OpenFOAM without having to close ParaView?
2) How to view the last run result in ParaView when opened again?
3) Is it possible to have ParaView open with multiple tabs (for different cases)?

[AtoHM]

1) you cannot "run" OpenFOAM "files" from Paraview. You open the .foam or .OpenFOAM file in the folder. This acts as an indicator to Paraview how to interprete the data in the folder -> as an OpenFOAM case.
2) You can select the displayed timestep in the toolbar at the top. Paraview can only display timesteps which have been written out to the disc. You cannot follow along each iteration, as long as you don't write the data out each step. Don't do that, unless you have alot of time and disc space. Once a new step has been written out, you must go to the .foam-Node in Paraview and hit "reload" to make PV detect the latest time steps. Whether you see the timesteps also depends if you run in parallel or not. If you run in parallel, you must select Case Type "decomposed case" at the .foam-Node in Paraview. Otherwise, you need to reconstruct the case to obtain a single timestep folder with the collected results from each processor folder.
3) Paraview does not have tabs. Instead you can run as many instances as you like. If you want two views side by side, you can split the viewport. At the top right of the default viewport, there are controls to split the view horizontally or vertically. Then you can display a case in the left view and another one in the right one, just load in another .foam file.

[Amirthaa]

1) Understood. I meant running in OpenFOAM, as in to work in OpenFOAM without having to close ParaView.
2) I shall check that.
3) Oh, yes. Thanks. I had assumed the viewport was just to view 1 case in different views.

[Yann]

Originally Posted by Amirthaa

1) Understood. I meant running in OpenFOAM, as in to work in OpenFOAM without having to close ParaView.

Open 2 terminals : one to run you case and another one to launch paraview

[Amirthaa]

Originally Posted by AtoHM

1) you cannot "run" OpenFOAM "files" from Paraview. You open the .foam or .OpenFOAM file in the folder. This acts as an indicator to Paraview how to interprete the data in the folder -> as an OpenFOAM case.

So I created a log file by simpleFoam > log.simpleFoam & but I'm unable to view .foam file in OpenFoam. What am I missing?
I have attached the image of folders list am seeing in paraview and in linux folder.

[Amirthaa]

What I view in Linux folders:

[Yann]

There are 2 readers for ParaView to open an OpenFOAM case:

1. The native reader from ParaView: it uses a empty file using the .foam extension to trigger the OpenFOAM reader in ParaView. You can create this file with the command touch myCase.foam. The name of the file does not matter, it is just a trick to tell ParaView it has to open the case with the OpenFOAM reader. This reader will allow you to load a decomposed case, so you don't have to reconstruct your case before loading it in ParaView (just select "Case Type : Decomposed case" in ParaView)
2. The paraFoam command launches ParaView with a another reader which is shipped with OpenFOAM. This reader won't let you load a decomposed case, so you will need to reconstruct the case first. It has other features though, like the ability to display cellZones.

You can use the native reader from ParaView and avoid create a .foam case by using the command paraFoam -builtin which basically start PataView with the native OpenFOAM reader.

Cheers,
Yann

[Amirthaa]

Okay. I understand a bit better now. I tried opening by the first method also now.
I now get an error, while executing simpleFoam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 400


SIMPLE: Convergence criteria found
        p: tolerance 0.0001
        U: tolerance 0.0001
        "(k|omega|epsilon)": tolerance 0.0001

Reading field p



--> FOAM FATAL IO ERROR:
size 112446 is not equal to the given value of 112474

Would you be able to help me on this?

[Yann]

There is a mismatch between the size of your mesh and the size of your variables.
Since it seems your simulation is starting at iteration 400, You are probably trying to restart a case after changing the mesh, or something like this.

If you want to start a simulation using previous results on a new mesh, you should use mapFields or mapFieldsPar to map the results on the new mesh before running the case.

Yann

[Amirthaa]

Noted. Yes, I'm restarting the case but I have not made any changes to the mesh.
mapFields is new to me. I shall check that.

[Yann]

If you didn't change anything, it should restart flawlessly.
But the error you get indicates there is something different somewhere between the moment you stopped the simulation and the moment you restarted it.

Have you modified anything? Or restarted the solver with a different command?

[Amirthaa]

I have changed the position of geometry inside the mesh. Other than that I don't think I have made any changes in any files or usage of commands.