CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

SimpleFoam with body force gravity

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   June 16, 2006, 07:02
Default Hello everybody, Did anybod
  #1
New Member
 
Alexander Jarosch
Join Date: Mar 2009
Location: Iceland
Posts: 6
Rep Power: 8
alexice is on a distinguished road
Hello everybody,

Did anybody already modify the simpleFoam solver to include a body force term, i.e. gravity. I would like to add that and look for some hints.

Thanks for all advice
alexice is offline   Reply With Quote

Old   June 16, 2006, 08:27
Default look at buoyantFoam, it is in
  #2
Senior Member
 
Markus Hartinger
Join Date: Mar 2009
Posts: 102
Rep Power: 8
hartinger is on a distinguished road
look at buoyantFoam, it is in there

markus
hartinger is offline   Reply With Quote

Old   June 16, 2006, 09:02
Default thanks, right I just look at t
  #3
New Member
 
Alexander Jarosch
Join Date: Mar 2009
Location: Iceland
Posts: 6
Rep Power: 8
alexice is on a distinguished road
thanks, right I just look at that. I'm new to OpenFoam so it might take me a while to get into the code. buoyantFoam uses a variable density as I understand it, whereas I treat a constant density case.

I want to let the fluid move driven by gravity. Is it maybe simpler to just define the pressure gradient instead of including it in the solver? I guess this is possible in OpenFoam ;-)
alexice is offline   Reply With Quote

Old   June 16, 2006, 09:58
Default twoLiquidMixingFoam is incompr
  #4
Senior Member
 
Markus Hartinger
Join Date: Mar 2009
Posts: 102
Rep Power: 8
hartinger is on a distinguished road
twoLiquidMixingFoam is incompressible, try that
hartinger is offline   Reply With Quote

Old   January 3, 2012, 10:11
Default
  #5
Member
 
Join Date: May 2010
Posts: 38
Rep Power: 7
Ladnam is on a distinguished road
Is this the last word in this case?

Is it not possible to model steady-state, single phase, incompressible, laminar flow with gravity in OpenFoam?
Ladnam is offline   Reply With Quote

Old   May 10, 2013, 03:27
Default
  #6
Senior Member
 
Dongyue Li
Join Date: Jun 2012
Location: Torino, Italy
Posts: 676
Rep Power: 8
sharonyue is on a distinguished road
Quote:
Originally Posted by Ladnam View Post
Is this the last word in this case?

Is it not possible to model steady-state, single phase, incompressible, laminar flow with gravity in OpenFoam?
I also want to try this. Did you find the solution?

Thanks
sharonyue is offline   Reply With Quote

Old   May 14, 2013, 01:03
Default
  #7
Senior Member
 
Tushar Chourushi
Join Date: Jul 2009
Location: IIT-Indore, India
Posts: 319
Blog Entries: 1
Rep Power: 9
Tushar@cfd is on a distinguished road
Quote:
Originally Posted by sharonyue View Post
I also want to try this. Did you find the solution?

Thanks
Quote:
Originally Posted by Ladnam View Post
Is this the last word in this case?

Is it not possible to model steady-state, single phase, incompressible, laminar flow with gravity in OpenFoam?
Did you get the solution?
Instead of variable density suppose I want constant density.
Do you think the answers in both cases will differ?
I too want to know the answer..

Last edited by Tushar@cfd; May 14, 2013 at 02:10.
Tushar@cfd is offline   Reply With Quote

Old   May 14, 2013, 11:44
Default
  #8
Member
 
Sachin Kanetkar
Join Date: Mar 2009
Posts: 57
Rep Power: 8
sachin is on a distinguished road
Quote:
Originally Posted by Tushar@cfd View Post
Did you get the solution?
Instead of variable density suppose I want constant density.
Do you think the answers in both cases will differ?
I too want to know the answer..
Hi Tushar,
I guess you might have already traced out solution....
Anyways if your rho is fixed you just have to add it as source term in UEqn.h() with g as vector.
u may define them in create Fields.h. So the efftect will be seen as source term in weight of fluid in only 1 momentum eq but rest would remaiin the same as before...
Correct me if i am wrong ...

Sachin
sachin is offline   Reply With Quote

Old   May 15, 2013, 00:32
Default
  #9
Senior Member
 
Tushar Chourushi
Join Date: Jul 2009
Location: IIT-Indore, India
Posts: 319
Blog Entries: 1
Rep Power: 9
Tushar@cfd is on a distinguished road
Quote:
Originally Posted by sachin View Post
Hi Tushar,
I guess you might have already traced out solution....
Anyways if your rho is fixed you just have to add it as source term in UEqn.h() with g as vector.
u may define them in create Fields.h. So the efftect will be seen as source term in weight of fluid in only 1 momentum eq but rest would remaiin the same as before...
Correct me if i am wrong ...

Sachin
Thanks for replying..

I have already done that thing with buoyantSimpleFoam... But later dropped the idea as it didn't suit my requirements and worked with Boussinesq approximation. If you see the code here variable density is needed for buoyancy..

I think I should say in detail, since I am working with buoyantBoussinesqSimpleFoam...

I have solution but these differs from the numerical approach of the papers. For a very simple case the results matches exactly with the journal papers. But for the case of complex geometry results are showing deviations from paper. Which I don't think is permissible, with the use of higher order schemes and since the results are reaching convergence(I have set below 1e-05 for all variable is my convergence criteria). When I happen to see the Isotherms and streamlines the dissipations seems to match with the paper but the gradT value is differs. It seems convective dissipation of heat in OF is more.

Anyways, I am trying to figure it out.

Is there anyone who has solved a complex case of natural convection (especially with buoyantBoussinesqSimpleFoam)?

Last edited by Tushar@cfd; May 15, 2013 at 07:28.
Tushar@cfd is offline   Reply With Quote

Old   May 15, 2013, 00:56
Default
  #10
Senior Member
 
Tushar Chourushi
Join Date: Jul 2009
Location: IIT-Indore, India
Posts: 319
Blog Entries: 1
Rep Power: 9
Tushar@cfd is on a distinguished road
Well,

Anyone successful in solving natural convection of complex geometry (like heat transfer inside a room with a source object).

If yes please, try to share your views.. Are you getting the exact results (as compared with numerical results of papers)?

Thanks in Advance..


Last edited by Tushar@cfd; May 15, 2013 at 07:28.
Tushar@cfd is offline   Reply With Quote

Old   May 15, 2013, 09:13
Default
  #11
Member
 
Sachin Kanetkar
Join Date: Mar 2009
Posts: 57
Rep Power: 8
sachin is on a distinguished road
Sounds interesting ... Can you share the data ... what is the complexity...
CAn you share the difference ...

Points you can check -
1. What is effect of variation in Tref in boussinesq approximation
2. What is your Rayliegh number ... is it very high .. in which case it would turbulent flow
3. Changes in mesh

Best Luck
Sachin
sachin is offline   Reply With Quote

Old   May 15, 2013, 23:32
Default
  #12
Senior Member
 
Tushar Chourushi
Join Date: Jul 2009
Location: IIT-Indore, India
Posts: 319
Blog Entries: 1
Rep Power: 9
Tushar@cfd is on a distinguished road
Quote:
Originally Posted by sachin View Post
Sounds interesting ... Can you share the data ... what is the complexity...
CAn you share the difference ...

Points you can check -
1. What is effect of variation in Tref in boussinesq approximation
2. What is your Rayliegh number ... is it very high .. in which case it would turbulent flow
3. Changes in mesh

Best Luck
Sachin
Condition1:
I didn't understand this. What do you mean by variation in Tref in boussinesq approximation? Can you please explain, what kind of variation you are talking about?


Condition 2:
I already shared the data check my post...
buoyantBoussinesqSimpleFoam

Condition 3:
Well, if I am right then mesh size won't have much impact on results in case of SIMPLE algorithm.

Last edited by Tushar@cfd; May 16, 2013 at 00:49.
Tushar@cfd is offline   Reply With Quote

Old   May 16, 2013, 07:47
Default
  #13
Member
 
Sachin Kanetkar
Join Date: Mar 2009
Posts: 57
Rep Power: 8
sachin is on a distinguished road
I was refering to your ref temperature/ambient temperature...
I understand that these solvers might have some problems with complex geometries but the case described doesnt really seems to be a complex geometry ...
For mesh, I dont know why it is not important. your concern from what understand is not something about no convergence but about dissipation of heat. So, if the mesh does capture the heated boundary condition, the results might improve.

To check if the OF is giving some problem, you can compare it with some other s/w.
With no real case results, we can keep guessing what you can try...

If I could still thing of any more ideas, I would keep you posted.
If you do solve your problem, let me know.

Best Luck,
Sachin
sachin is offline   Reply With Quote

Old   May 16, 2013, 08:07
Default
  #14
Senior Member
 
Tushar Chourushi
Join Date: Jul 2009
Location: IIT-Indore, India
Posts: 319
Blog Entries: 1
Rep Power: 9
Tushar@cfd is on a distinguished road
I am very confident about my results.

Anyways, I am trying to figure out the same with other options.

Last edited by Tushar@cfd; May 16, 2013 at 10:14.
Tushar@cfd is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
DPM Body Force Sandilya Garimella FLUENT 1 April 8, 2008 03:30
Flow under gravity force danvica OpenFOAM Running, Solving & CFD 0 December 12, 2007 11:22
Body force Jacob FLUENT 0 August 4, 2003 16:38
how to treat the gravity force Angela Main CFD Forum 0 January 17, 2003 04:39
UDF-Body Force Fluent_User FLUENT 0 August 9, 2002 09:07


All times are GMT -4. The time now is 00:41.