[arif.hmc3]

This error occur while solving the nozzle flow , I am a bignner can someone tell me how I resolve this issue, Yours suggesion will be highly appreciated, Thanks


"
ERROR #002100048 has occurred in subroutine SU_BNEXT. |
| Message: |
| All vertices for a fluid domain lie on boundaries. This is |
| considered to be a fatal error because control volume gradients |
| cannot be calculated, leading to serious discretization error. |
| |
| A common cause for this error is a mesh which is only one |
| element thick, without symmetry or 1:1 periodicity on the lateral |
| boundaries. If you have this situation, and the domain is |
| two-dimensional, please change the lateral boundary conditions |
| to symmetry or 1:1 periodicity. Alternatively, for |
| three-dimensional simulations, please ensure that your mesh |
| has at least two elements across. |
| |
| Execution is terminating. This error message can be bypassed by |
| setting the expert parameter 'boundary vertex check = f', but |
| be aware that doing so may lead to sigificant solution error."

[ghorrocks]

The error message is pretty clear, isn't it? It tells you exactly what you need to do.

[arif.hmc3]

Sorry , I am a bignner, but now a bit learned..

[ghorrocks]

OK, let me repeat what the message says:

You cannot have a domain which is 1 element thick. You will need to make it a few elements thick.

Note you can have a 1 element thick domain with symmetry and periodic boundaries. But all other types of boundary are not possible.

[arif.hmc3]

yes, I got it, Thanks for reply...

[arif.hmc3]

Dear Sir, Can u tell me plz how to increase the near wall mesh density in nozzle ?i am attaching geometry along with some rough mesh.

[ghorrocks]

Make the mesh finer. It is a pretty simple concept.

I also note that your mesh has some massive jumps in size. This is bad. You need to transition the mesh when you change size.

[arif.hmc3]

Thanks for your reply. Actully I Dont know how to make fine mesh near the wall in ICEM. I want to capture sepration of flow , so need more dense mesh near wall. Plz dont mind , I know I mputting very basic question but I try to that but not succeful yet.

[ghorrocks]

This is all covered in the ICEM tutorials. You can get them on the ANSYS customer page on the ANSYS website.

[hesamking]

Try switching to local parallel run in the CFX-solver instead of serial and the simulation will run without any problem!!!!
Hesam

[ermiasa100@gmail.com]

dear sir, the same message occurred in my simulation please tell me the step how to thick
ERROR #002100048 has occurred in subroutine SU_BNEXT. |
| Message: |
| All vertices for a fluid domain lie on boundaries. This is |
| considered to be a fatal error because control volume gradients |
| cannot be calculated, leading to serious discretization error. |
| |
| A common cause for this error is a mesh which is only one |
| element thick, without symmetry or 1:1 periodicity on the lateral |
| boundaries. If you have this situation, and the domain is |
| two-dimensional, please change the lateral boundary conditions |
| to symmetry or 1:1 periodicity. Alternatively, for |
| three-dimensional simulations, please ensure that your mesh |
| has at least two elements across. |
| |
| Execution is terminating. This error message can be bypassed by |
| setting the expert parameter 'boundary vertex check = f', but |
| be aware that doing so may lead to sigificant solution error."

[ghorrocks]

The error message is pretty clear, isn't it? It tells you exactly what you need to do.

I think I have said that before......

[ermiasa100@gmail.com]

yes, sir, you said it but the response is not clear,i need more explanation, please, how to thick more elemnts

[Gert-Jan]

If this is an ICEM problem, then better ask in the ANSYS Meshing and Geometry forum, and add some pictures to see what you try to do.

[ermiasa100@gmail.com]

okay thankyou

[ermiasa100@gmail.com]

any one can you help me

[Gert-Jan]

Your geometry (or at least a part) is 2D. Meaning, you have a surface mesh. In Fluent you can do this, not in CFX. In CFX your 2D part requires an element in the third direction to create a volume. This can be 1 element. Then you can solve your 2D case using CFX with symmetry BC on the front and the back surface.

However, your problem seems not to be in the solver, but in the geometry or in the mesher. So if you don't know how to solve this, then go to the appropriate forum and ask there with some pictures. A picture says more than thousand words.

https://www.cfd-online.com/Forums/ansys-meshing/

[Opaque]

If you are modeling a 2D case (with one element thick), and you have the wrong boundary conditions on the "2D planes", you will get this error.

The message says clearly, that your boundary condition on those planes can ONLY be symmetry, or translational periodicity using a 1:1 option. If you think those options do not apply to you, you likely do not have a 2D problem and your whole approach is incorrect from the start.