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pressure iteration didnt converge

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Old   December 25, 2013, 20:41
Default pressure iteration didnt converge
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melek
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how can I edit this error? what is that mean?

Solver Messages: pressure iteration did not converge in itmax= 100 iterations
at time= 1.03537E-02 cycle= 90 iter= 100 nocon= 0
epsi= 4.083E-01 maximum residual= 5.539E-01 at i= 124 j= 2 k= 70 block= 5
convective flux exceeded stability limit
at t= 3.2759E-02 cycle= 306 iter= 5 delt= 3.4220E-05 mesh block 5
restarting cycle with smaller time step
maximum failure ratio = 2.95606E+00 is in z-coordinate direction
at cell ( 233, 2, 215) mesh block 5
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File Type: txt warning error.txt (23.7 KB, 37 views)

Last edited by melek; December 26, 2013 at 06:36.
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Old   December 30, 2013, 03:30
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Mohammadreza
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Dear Melek
The solver, solve 100 times an iteration, if the stop criteria accepted then go to next iteration, but if it unaccepted so stop the solving. So, no way to get the accurate simulation results.

Regards,
M. R. sharifabadi
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Old   January 11, 2014, 12:49
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Thank you Sharifabadi. so do you have any idea how can I correct the mistake... I tried to increase GMPRES number and decrease messh sell sizes. However the simulation runned with 2 gb and again took this message. pressure iteration didnt converse itmax =100
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Old   January 12, 2014, 04:07
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As far as I know, there is no way to take away from this problems, restart your simulation from first ( call STL files ) and do simulation again may you haven't problem.

Don't hesitate if you have any question.
this is my email address: mo.sharifabadi@gmail.com
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Old   March 7, 2014, 01:50
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Have you corrected you problem? i am stuck in such a situaiton too
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Old   March 26, 2014, 10:13
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Do you have different mesh blocks in your model ?

It can be due to connection problems between mesh blocks (or bad cell size ratio).
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Old   March 26, 2014, 20:59
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Quote:
Originally Posted by macsim View Post
Do you have different mesh blocks in your model ?

It can be due to connection problems between mesh blocks (or bad cell size ratio).
I didn't add any mesh plane to the mesh block,just let mesh generator do the job.
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Old   March 27, 2014, 06:09
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If you have thin thickness, it could be interesting to add mesh planes.

Usually, a list of messages as your comes from bad mesh conditions. When you analyze results, geometry visualization is good ?
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Old   March 28, 2014, 10:15
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Thank you for answers, mesh and geo was crossed I thınk but only I wrote relaxatıon factor = 0,5 and downed tıme step all problems are over
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Old   March 28, 2014, 10:18
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And mesh was strong I thınk chanced mesh desıgn
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Old   March 28, 2014, 10:24
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thank you for answers
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Old   September 18, 2019, 21:15
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Hey melek ...can u please tell me in detail what exactly did u do to overcome that problem..because i am facing the same problem for days now? Please help..
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Old   October 5, 2019, 17:37
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Hi Nauman,

Could you find the solution?

Thanks,
Yasemin
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Old   November 19, 2019, 11:40
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Quote:
Originally Posted by melek View Post
how can I edit this error? what is that mean?

Solver Messages: pressure iteration did not converge in itmax= 100 iterations
at time= 1.03537E-02 cycle= 90 iter= 100 nocon= 0
epsi= 4.083E-01 maximum residual= 5.539E-01 at i= 124 j= 2 k= 70 block= 5
convective flux exceeded stability limit
at t= 3.2759E-02 cycle= 306 iter= 5 delt= 3.4220E-05 mesh block 5
restarting cycle with smaller time step
maximum failure ratio = 2.95606E+00 is in z-coordinate direction
at cell ( 233, 2, 215) mesh block 5
Also, try using a much smaller initial time-step.
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Old   November 21, 2019, 21:42
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Yes Yasmin, all i needed to do was create two mesh blocks seperately for the geometry and the bigger domain.. and also need to take care that the boundaries of the smaller mesh block cells coincide with the boundaries of the bigger mesh block cells...
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Old   December 18, 2019, 02:10
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Thank you!
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Old   December 18, 2019, 02:12
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Quote:
Originally Posted by elyasmin View Post
Hi Nauman,

Could you find the solution?

Thanks,
Yasemin
You are welcome
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