|
[Sponsors] |
June 10, 2013, 00:25 |
Converge
|
#1 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
hi,
I'm study on external flow in sand domain, does i always need to wait the solution until converge. As it take longer time to converge for external flow and in transient state.. |
|
June 10, 2013, 01:33 |
|
#2 | |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
Quote:
if you want final solution, you must use steady-state solver not transient. Regards |
||
June 10, 2013, 01:40 |
|
#3 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
when i use steady state, error will be detected:
divergence detected in AMG solver: k increasing relation sweep Why this error will appear?? |
|
June 10, 2013, 01:54 |
|
#4 |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
If all settings are ok, usually this error appears when initial conditions for k and epsilon are incorrect. Plz change initial conditions for k & epsilon.
|
|
June 10, 2013, 03:11 |
|
#5 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
i'm setting :
Inlet. Turbulent intensity = 5%. Turbulent viscosity ratio= 10 Outlet turbulent intensity=1% turbulent viscosity ratio= 10 Any problem in my setting ? |
|
June 10, 2013, 03:21 |
|
#6 | |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
Quote:
http://www.cfd-online.com/Forums/ope...urbulence.html Regards |
||
June 10, 2013, 07:47 |
|
#7 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
So, I should lower my k and epsilon value. Does I need to change relaxation values?
Why should I change my k and epsilon value? Actually what value is the most possible for k and epsilon |
|
June 10, 2013, 08:27 |
|
#8 |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
Yes. you should select lower value for k and epsilon. initial value of k and epsilon are depended to your problem. but initial values havent any effect on final solution. so change value of k and epsilon to 0.001 and 0.0001 respectly.
Regards |
|
June 11, 2013, 00:00 |
|
#9 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
I'm trying to lower my k and epsilon in my solution control, however the error (divergent detected) become more faster (in lesser iteration calculation).
|
|
June 11, 2013, 00:29 |
|
#10 |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
Is your mesh dimension correct?
|
|
June 11, 2013, 03:06 |
|
#11 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
how to check whether why mesh is correct?? There is no warning on my mesh,,, Do u mind send me your email...i will send my case data for u, to better understanding on my fluent setting.
|
|
June 11, 2013, 03:27 |
|
#12 |
New Member
sina
Join Date: Sep 2011
Posts: 28
Rep Power: 14 |
I send my mail for you (private message). please send your geometry dimension too.
tnx |
|
June 26, 2013, 04:22 |
|
#13 |
Member
tang
Join Date: Jan 2013
Posts: 35
Rep Power: 13 |
i already send to u past two week..
|
|
September 21, 2013, 22:53 |
help
|
#14 |
New Member
guilin han
Join Date: Jun 2013
Posts: 2
Rep Power: 0 |
||
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
can't converge in FLUENT | ok___ko | FLUENT | 1 | April 30, 2013 03:47 |
Gmres fails to converge, but LU is fine | sbabbi | Main CFD Forum | 1 | April 11, 2013 09:54 |
k and epsilon were hard to converge in multiphase model of Fluent | Yanlong Li | ANSYS | 0 | January 2, 2013 06:25 |
HELP !In relaxtion factor converge is taken or not | MANOJ KUMAR | FLUENT | 5 | September 22, 2005 05:16 |
Converge problem for multiphase flow | Jen | FLUENT | 4 | July 20, 2005 17:52 |