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#1 |
New Member
Seon Hye
Join Date: Feb 2012
Location: South Korea
Posts: 18
Rep Power: 14 ![]() |
Hi, everyone.
I am new in OF and I study and simulate OF for two month. (OF 2.1.0) I want to run the Small Horiziontal Axis Wind Tubine case including tower, so I chose pimpleDyMFoam as solver and kOmegaSST as turbulence model. First, I ran the case without a tower to know the proper condition to simulate, but the result always diverged, increasing Courant Number and other things. I decided to change the solver to MRFSimpleFoam. But I met the trouble that time step continuity error increase with the iterations. I tried to find the reason and found that, in this forum, some people had the similar problem. They had 0 value as AMI: patch source weights min, but I had about 0.1 value Their solution is to adjust and improve the mesh. So I adjusted the meshes(AMI) that had the odd values, but the results also became wrong and time step continuity error increase with time. AMI: Patch source weights min/max/average = 0.679762, 1, 0.998602 AMI: Patch target weights min/max/average = 0.154367, 1, 0.998088 Before I adjusted the mesh, I tried a lot of things to solve the problem. For example, I had changed fvScheme, fvSolution, time step, decomposePar method, initial condition, Patch type .......... All of those are useless. I have studies OF alone and there are no one who can know OF well. Is there anyone who can advise me about simulation of wind turbine with OF? AND I want to know the exact meaning of time step continuity error and AMI weight. Last edited by ysh1227; April 16, 2012 at 06:58. |
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#2 |
Senior Member
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 556
Rep Power: 27 ![]() |
Hi
You can use this as an example. http://dl.dropbox.com/u/15968063/3DStruct.TSR1.0.tar.gz That is a 3bladed VAWT with a NACA0012 profile. Its done using 1.6-ext but you can change the GGI to AMI and it should work with 2.1. Also I was using transientSimpleDyMFoam and not pimpleDyMFoam. Also you can't use MRF for a VAWT. When the MRF zone is perpendicular to the flow is generates flow that looks like flow over a cylinder. I cant go into the specifics about this other than tell you that it wont work. The same problem exists in Fluent.
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Linnemann PS. I do not do personal support, so please post in the forums. |
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#3 |
New Member
Seon Hye
Join Date: Feb 2012
Location: South Korea
Posts: 18
Rep Power: 14 ![]() |
Thanks, Linnemann.
![]() I will check the example of VAWT right now. hum..I have another question. Do you know the specific means about AMI weights and time step continuity error? |
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#4 |
Senior Member
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 556
Rep Power: 27 ![]() |
The best thing you could was to upload the case as I've done with the VAWT case and have people have a look at the mesh/setup.
The continuity issues is often related to the mesh and fvSchemes/fvSolutions and BC's so in general it can be anything so it can be a hard one to track down with the little info you have given. Following this guide will most likely get you more help. http://www.cfd-online.com/Forums/ope...-get-help.html
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Linnemann PS. I do not do personal support, so please post in the forums. |
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#5 |
New Member
Seon Hye
Join Date: Feb 2012
Location: South Korea
Posts: 18
Rep Power: 14 ![]() |
Thank you
![]() This is the first time to question on the web, so I'm sorry that I didn't give you the necessary info required to solve the trouble. First, as I said, I'll check your case and my case again, and then I'll upload in the way you suggest. I hope that I could learn more from you. |
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#6 |
Senior Member
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 17 ![]() |
what is AMI and GGI ?
and what would be steps converting GGI blocks in file to AMI? Some guidance plz. regards |
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#7 |
Member
Charles
Join Date: May 2011
Location: France
Posts: 77
Rep Power: 15 ![]() |
Thanks linnemann for sharing your case,
Unfortunately, I didn't succeed in running it. Would you give us a guidance to get it working with AMI or even in GGI or repost this case updated with AMI ?? Thanks, Charles |
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#8 |
Senior Member
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 556
Rep Power: 27 ![]() |
Just unpack it and use it with OF1.6-ext pimpleDyMFoam solver or compile transientSimpleDyMFoam and use that.
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Linnemann PS. I do not do personal support, so please post in the forums. |
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#9 | |
Member
Andreas Wendy
Join Date: Aug 2012
Posts: 73
Rep Power: 14 ![]() |
Quote:
i just tried to run this case and i get an floating point exception. can this caused by a computer problem? i do not get it in my mind why on a different PC the calculation works but not ion mine. i get these error more often. best wishes Andy |
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#10 | |
Senior Member
M. Montero
Join Date: Mar 2009
Location: Madrid
Posts: 155
Rep Power: 17 ![]() |
Could you upload the example another time?
I am trying to simulate a HAWT but pimpleDymFoam and CFL limitations is a nightmare when I need results asap. Quote:
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