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shanxuewenjdx May 30, 2012 03:34

CFX-Solver
 
3 Attachment(s)
Hi.

The solver stopped my simulations after appr. 4 timesteps given the following error message:

An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver could not be started, or exited with return |
| code 255: . No results file has been created.


Is there any thing that contribute to that failure?
1、improper mesh ?
2、some settings which have a close relation with numerical stability when the continuity, momentum, energy and mass transport equations are solved together
Many thanks!

jwillie2000 May 30, 2012 03:42

It could as well be a license problem. So check your license server to make sure you have available license. Jimmy

shanxuewenjdx May 30, 2012 04:15

Quote:

Originally Posted by jwillie2000 (Post 363744)
It could as well be a license problem. So check your license server to make sure you have available license. Jimmy

I suppose there is nothing to do with my license.
But other factors are responsible for the failure.

p.galimutti May 30, 2012 05:19

I can say this is DEFINITELY not a solver/mesh failure. It might be a memory/license issue. try increasing the default memory from 1.0 to 2.0

shanxuewenjdx May 30, 2012 06:16

If it's the memory issue,there would be some warnings saying that "there is not enough memory on the computer".
I have used my friends' computer, the message is also accurate the same like this.

p.galimutti May 30, 2012 06:23

try this....

start cfx stand alone. SAVE THE PROJECT!

import your mesh and definition file into this new project.

try running now ....don't use wb

jwillie2000 May 30, 2012 07:21

I did get a similar error but it has been long and i am trying to remember what was wrong. Have you checked to see whether your time step has been adequately given? It could be the value there (run time) is not adequate. Are u doing your unsteady simulation from a converged steady state one? Jimmy

shanxuewenjdx May 31, 2012 03:14

Quote:

Originally Posted by jwillie2000 (Post 363805)
I did get a similar error but it has been long and i am trying to remember what was wrong. Have you checked to see whether your time step has been adequately given? It could be the value there (run time) is not adequate. Are u doing your unsteady simulation from a converged steady state one? Jimmy

Thanks for your answer.
My simulation is unsteady.
Because the rotate speed of the gear is 2000r/min, the time step,that is dt, is (1/400)[s]/30 (1/400 is the time for each gear to pass through,and I divide the time into 30 steps) and total time is (12/400)[s] which means a period time.
So what can I do?

jwillie2000 May 31, 2012 06:58

Hi, my suggestion would be to look for a similar tutorial in CFX or contact ANSYS for support. Not sure whether you have a local coordinate system about which your model is rotating? I think that might be creating the problem.

shanxuewenjdx June 3, 2012 10:03

Quote:

Originally Posted by p.galimutti (Post 363794)
try this....

start cfx stand alone. SAVE THE PROJECT!

import your mesh and definition file into this new project.

try running now ....don't use wb

Thanks for your answer.
Would you explain it more specifically? I can't not understand your words fully.

shanxuewenjdx June 3, 2012 10:06

Quote:

Originally Posted by p.galimutti (Post 363794)
try this....

start cfx stand alone. SAVE THE PROJECT!

import your mesh and definition file into this new project.

try running now ....don't use wb

Thanks for your answer!
Would you explain it more specifically? I was confused with your words.

shanxuewenjdx June 3, 2012 10:09

Quote:

Originally Posted by shanxuewenjdx (Post 363742)
Hi.

The solver stopped my simulations after appr. 4 timesteps given the following error message:

An error has occurred in cfx5solve: |
| |
| The ANSYS CFX solver could not be started, or exited with return |
| code 255: . No results file has been created.


Is there any thing that contribute to that failure?
1、improper mesh ?
2、some settings which have a close relation with numerical stability when the continuity, momentum, energy and mass transport equations are solved together
Many thanks!

+--------------------------------------------------------------------+
| Warning! |
| |
| After waiting for 60 seconds, 1 solver manager process(es) appear |
| not to have noticed that this run has ended. You may get errors |
| removing some files if they are still open in the solver manager. |
+--------------------------------------------------------------------+



Above is more information about my model>

p.galimutti June 4, 2012 13:33

My reply was assuming you're using workbench. This kind of problem happened to me when i'm transferring files from a local computer to server. There were possibly some files lost.

You know you can use CFX in standalone mode without using WB. It will in Programfiles>ANSYS>Fluid Dynamics>CFX (assuming you are using windows). And then import your mesh file and the ccl file and see if it works

HTH

rikio June 5, 2012 04:19

By looking into the snapshot of the model and notice message, it seems that there is no adequate fluid flow channel to make it through, and the inflow back to inlet which is different from the BC you set, that is why an artificial wall was built.

shanxuewenjdx June 5, 2012 22:42

Quote:

Originally Posted by p.galimutti (Post 364689)
My reply was assuming you're using workbench. This kind of problem happened to me when i'm transferring files from a local computer to server. There were possibly some files lost.

You know you can use CFX in standalone mode without using WB. It will in Programfiles>ANSYS>Fluid Dynamics>CFX (assuming you are using windows). And then import your mesh file and the ccl file and see if it works

HTH

Thanks. My model was in CFX stand alone.

shanxuewenjdx June 5, 2012 23:33

Quote:

Originally Posted by rikio (Post 364770)
By looking into the snapshot of the model and notice message, it seems that there is no adequate fluid flow channel to make it through, and the inflow back to inlet which is different from the BC you set, that is why an artificial wall was built.

I have changed the settings ,both the "outlet" and "inlet", but the message in CFX-Solver still the same shown on Fig above.

singer1812 June 6, 2012 12:46

Forget the memory errors.

Your problem is definately setup wrong or ill-formed. CFX is blocking off the inlet to keep flow from trying to travel back out.

Are your gears turning? Is there flow through even if the gears are not turning? Is your inlet set right (i.e. you didnt specify a cartisian component of the flow to force it out?)

shanxuewenjdx June 25, 2012 00:32

Quote:

Originally Posted by singer1812 (Post 365090)
Forget the memory errors.

Your problem is definately setup wrong or ill-formed. CFX is blocking off the inlet to keep flow from trying to travel back out.

Are your gears turning? Is there flow through even if the gears are not turning? Is your inlet set right (i.e. you didnt specify a cartisian component of the flow to force it out?)

QUOTE]Thanks a lot.If the gear is not turning,the total fluid area is static which is the initial state of fluid area.

shanxuewenjdx June 25, 2012 00:36

1 Attachment(s)
Quote:

Originally Posted by shanxuewenjdx (Post 368095)
QUOTE]Thanks a lot.If the gear is not turning,the total fluid area is static which is the initial state of fluid area.

what do you mean by the inlet setting?you can check the model before meshed. it's the "coordinate 0",which was set in fluid area.

shanxuewenjdx June 25, 2012 04:25

Could anyone offer some advice on my problem?I'm in great gratitude .


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