[Danny_cfd]

Good day Foamers,
Thank you for reading my post.

I have a very simple and repeatedly asked question. Sorry I did not find any satisfactory solution yet. I have axisymmetric 2D mesh of a simple bubble enclosed in rectangular domain. I just consider 1/4 portion for reduction. I make the mesh in fluent in 2d plane and save it in ascii format .msh. Afterwards i used https://github.com/krebeljk/wedgePlease utility to make it axisymmetric grid for wedge boundary. Every thing goes successful.

The problem started afterward. When i solve the generated grid for my case (Which is correct), I get the following Error.

Wedge patch 'wedge1' is not planar.
At local face at (10.6613 -277.657 0.465485) the normal (-0.0436194 -1.58485e-17 0.999048) differs from the average normal (-0.0436195 -4.45833e-08 0.999048) by 2.40193e-14
Either correct the patch or split it into planar parts

I tried to dig out the problem and after doing certain recommendations like:
writeFormat binary; //<-KEEP binary
writePrecision 12; //<- Make it up to 12 or more if you want

I came to the conclusions that actually it is because of the common boundary that is generated by default frontAndBackPlane which remains empty in most cases. However in my case it is Wedge boundary condition.

Now the problem is how to split this fron and back plane to two wedge boundary in polymesh file in constant folder.

If anybody senior can recommend me a very simple method to get rid of this problem, I would be extremely indebted to you. Other way around i know that i can solve this simple case in ANSYS by modelling 3D mesh with 5 degree of wedge and import 3D mesh and name the two wedges separately. But it will not work for my future understanding of the problems.

Thank you so much for reading my post.
Regards,
Danny

[Mansur]

Hi Danny,

I have experienced the same problem after creating a wedge domain using makeAxialMesh.

In my experience, this was not an Error but a Warning. The terminal would output this Warning for every face on the patch and it takes forever to get past it. However, once it's done displaying it, you can run and manipulate your case as usual.

This is not a fix but something that will allow you to skip the warnings:
When running any application, redirect the output to a log file, e.g.
simpleFoam >log.simple
paraFoam >log.para
reconstructPar >log.rec

The application will launch immediately.

I hope this is helpful.

Mansur

[Danny_cfd]

Originally Posted by Mansur

Hi Danny,

I have experienced the same problem after creating a wedge domain using makeAxialMesh.

In my experience, this was not an Error but a Warning. The terminal would output this Warning for every face on the patch and it takes forever to get past it. However, once it's done displaying it, you can run and manipulate your case as usual.

This is not a fix but something that will allow you to skip the warnings:
When running any application, redirect the output to a log file, e.g.
simpleFoam >log.simple
paraFoam >log.para
reconstructPar >log.rec

The application will launch immediately.

I hope this is helpful.

Mansur

Hello Mansur,
First of all thank you so much for your detailed Answer. I do understand how to get rid of this warning and i redirect my application once again as you suggested. It seems to work and i can get rid of warning. But it lead me to another Fatal Error which i was ignoring.

wedge frontAndBackPlanes centre plane does not align with a coordinate plane by 1 .

I think may be i am getting it because i may have done some inconsistency with the coordinate system while drawing 2d case in Ansys.
Can you suggest me any solution to this too?

I am extremely indebted to you for your kind reply.

Regards,
Danny

[Mansur]

Glad to help!

How does your domain look after using wedgePlease? I am not familiar with this application, so I don't know how well it works.

I would make sure to check the mesh after each step:
1) After converting the Ansys mesh to OpenFOAM: make sure the 2D mesh you created in Ansys was extruded into 3D for OpenFOAM.
2) After using the wedgePlease, inspect the mesh visually and check the patches using paraView.

Do you think it's possible to create the initial mesh using blockMesh?
Check out this tutorial, I think the domain you described can be achieved with these shapes.

Best,
Mansur

[Danny_cfd]

Originally Posted by Mansur

Glad to help!

How does your domain look after using wedgePlease? I am not familiar with this application, so I don't know how well it works.

I would make sure to check the mesh after each step:
1) After converting the Ansys mesh to OpenFOAM: make sure the 2D mesh you created in Ansys was extruded into 3D for OpenFOAM.
2) After using the wedgePlease, inspect the mesh visually and check the patches using paraView.

Do you think it's possible to create the initial mesh using blockMesh?
Check out this tutorial, I think the domain you described can be achieved with these shapes.

Best,
Mansur

Hello Mansur, Thank you so much for being this much nice to my post. Actually, I enjoy your informative responses about my problem.

Regarding your kind response, Can you please have a look to my other post about the topic.
[Fatal Error] wedge frontAndBackPlanes centre plane does not align with a coordinate

I have attached my Grid in this post after the wedge please program. Yeah i also follow the same steps as your suggested while importing mesh from the ANSYS. I first import and used fluentMeshToFoam command to get a planner grid in z axis. I run the case and found it correct. After that i run the wedge please option as you suggested and saw the grid in Paraview as you can see in the attached file. The error suggested that my coordinate plan is not in the middle of the two planes so i went back in ANSYS and offset my coordinate by o.5 mm. Now you can see in the figure that my coordinate plan is exactly in the middle. However, the error still persists. Therefore, I would like to know how to deal with this problem. Thank you so much for your nice reply.

Regards,
Danny

[Mansur]

I looked at your mesh in the post you linked and I think this is the problem:
The makeAxialMesh application (on which the wedgePlease seems to be based) assumes that the boundary that is the symmetry axis is a straight line. My guess is that the wedge boundary condition has the same requirement.

See the Usage section here for makeAxialMesh.

You have a circular section in your symmetry axis.
To verify if this is in fact causing the error you can create your mesh without the circular section and try the same procedure (fluentMeshToFoam then wedgePlease).

Best,
Mansur