CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

Can laplacianFoam solve transient heat conduction equation?

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

Like Tree1Likes
  • 1 Post By HPE

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 30, 2020, 14:52
Default Can laplacianFoam solve transient heat conduction equation?
  #1
Member
 
granzer
Join Date: Apr 2016
Posts: 58
Rep Power: 5
granzer is on a distinguished road
It is my understanding that the laplacianFoam solver is used to solve the Laplace equation that arises during some modeling. But Laplace equation doesn't have a transient term or source term. So how can the laplacianFoam solve the transinet heat conduction equation? Shouldn't it be named 'diffusionFoam'?
granzer is offline   Reply With Quote

Old   February 13, 2020, 18:33
Default
  #2
HPE
Senior Member
 
Herpes Free Engineer
Join Date: Sep 2019
Posts: 298
Rep Power: 3
HPE is on a distinguished road
I would create a feature request issue in GitLab.

Having said that, usually, once a name for a functionality is released, it stucks even though more suitable alternatives emerge in the course of time, because of a virtual must to ensure the backward compatibility. Workflows of users should not be broken unless becomes a must.

If there would be very few users for OF, it would be very easy to make such changes. OF has a large habitat nevertheless, so any change will disturb the users and developers.

So why bother? Living with it is wise for such matters.
granzer likes this.
__________________
Kind regards,
HPE

The OpenFOAM community is the biggest contributor to OpenFOAM; not person A or B. Let's report bugs or issue feature requests in GitLab-OpenFOAM.

Please `design` your questions well. Such effort always pays off well for inquirers and `helpmate`s:
How to create a Minimal, Reproducible Example,
How to give enough info to get help.
HPE is offline   Reply With Quote

Old   February 18, 2020, 05:51
Default
  #3
Super Moderator
 
Tobi's Avatar
 
Tobias Holzmann
Join Date: Oct 2010
Location: Augsburg
Posts: 2,336
Blog Entries: 6
Rep Power: 39
Tobi has a spectacular aura aboutTobi has a spectacular aura about
Send a message via ICQ to Tobi Send a message via Skype™ to Tobi
Dear all,

I cannot agree about the statement that the laplacianFoam does not include the time derivative. So if you check the code we certainly see:

Code:
fvScalarMatrix TEqn
(
    fvm::ddt(T) - fvm::laplacian(DT, T)
    ==
    fvOptions(T)
);
I clearly can see the time derivative. Nevertheless, I have to say that for temperature depended on properties, the solver is not suited. So summing up:
  • Time derivative available
  • Laplacian term available
  • fvOptions for source / sink modeling available
__________________
Keep foaming,
Tobias Holzmann
Tobi is offline   Reply With Quote

Old   February 18, 2020, 08:24
Default
  #4
Member
 
granzer
Join Date: Apr 2016
Posts: 58
Rep Power: 5
granzer is on a distinguished road
Quote:
Originally Posted by Tobi View Post
Dear all,

I cannot agree about the statement that the laplacianFoam does not include the time derivative. So if you check the code we certainly see:

Code:
fvScalarMatrix TEqn
(
    fvm::ddt(T) - fvm::laplacian(DT, T)
    ==
    fvOptions(T)
);
I clearly can see the time derivative. Nevertheless, I have to say that for temperature depended on properties, the solver is not suited. So summing up:
  • Time derivative available
  • Laplacian term available
  • fvOptions for source / sink modeling available
Laplacianfoam solver does include the time derivative, but my question was regarding the Laplace equation which doesn't include a time derivative. Renaming the solver may be difficult, but it should be mentioned somewhere that it's not the Laplace equation but the diffusion equation which is being solved in the Laplaicanfloam solver.
granzer is offline   Reply With Quote

Old   February 18, 2020, 14:19
Default
  #5
HPE
Senior Member
 
Herpes Free Engineer
Join Date: Sep 2019
Posts: 298
Rep Power: 3
HPE is on a distinguished road
Would you please make a feature/documentation request in GitLab, if possible, then by referring this CFD-Online thread: GitLab-Issuer.
__________________
Kind regards,
HPE

The OpenFOAM community is the biggest contributor to OpenFOAM; not person A or B. Let's report bugs or issue feature requests in GitLab-OpenFOAM.

Please `design` your questions well. Such effort always pays off well for inquirers and `helpmate`s:
How to create a Minimal, Reproducible Example,
How to give enough info to get help.

Last edited by HPE; February 18, 2020 at 17:52.
HPE is offline   Reply With Quote

Old   February 18, 2020, 17:45
Default
  #6
Super Moderator
 
Tobi's Avatar
 
Tobias Holzmann
Join Date: Oct 2010
Location: Augsburg
Posts: 2,336
Blog Entries: 6
Rep Power: 39
Tobi has a spectacular aura aboutTobi has a spectacular aura about
Send a message via ICQ to Tobi Send a message via Skype™ to Tobi
Ah got it. Sorry.

So actually the laplacianFoam should not include the time derivative. I am not sure but I had the feeling that it was once without the time derivative. Nevertheless... I got your point

If I am still not on the right way, please just write down the equation
Tobi
__________________
Keep foaming,
Tobias Holzmann
Tobi is offline   Reply With Quote

Reply

Tags
heat conduction, laplace equation, laplacianfoam

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fluent do not use my velocity field(by UDF) to solve energy equation tangleiplus Fluent UDF and Scheme Programming 6 January 21, 2019 22:28
mass flow in is not equal to mass flow out saii CFX 12 March 19, 2018 06:21
non Fourier heat conduction (hyperbolic heat conduction) ars511 FLUENT 1 May 26, 2017 23:14
Error - Solar absorber - Solar Thermal Radiation MichaelK CFX 12 September 1, 2016 06:15
Setting the height of the stream in the free channel kevinmccartin CFX 10 July 9, 2015 22:36


All times are GMT -4. The time now is 08:58.