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

Different Implementation in solving pEqn

Register Blogs Community New Posts Updated Threads Search

Like Tree8Likes

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 23, 2009, 12:46
Default
  #21
Senior Member
 
Nishant
Join Date: Mar 2009
Location: Glasgow, UK
Posts: 166
Rep Power: 17
nishant_hull is on a distinguished road
Hi Matvej

I have advanced a bit ahead with my last problem. The previous error is sorted out. it was because of the difference in meshing and boundary condition.

However I am still wondering with the question of different implementation of p-equation. I mean..
when we use phi in pEqn (), we use
phi += pEqn.flux();
And when we use phid etc then we use
phi = pEqn.flux();

I am still wondering why?? Any hint please?

regards,
Nishant
nishant_hull is offline   Reply With Quote

Old   November 5, 2009, 14:16
Default
  #22
Senior Member
 
mkraposhin's Avatar
 
Matvey Kraposhin
Join Date: Mar 2009
Location: Moscow, Russian Federation
Posts: 355
Rep Power: 21
mkraposhin is on a distinguished road
Hi, I'm very sorry for late reply (too much work).
Anyway, if this answer is still needed:

when we update velocity (phi = velocity*density*area) in diffusion pressure equation, we mean that dU ~ const * grad(dp). If we are using convection-diffusion equation for pressure: ddt(psi,p) + div(phi_d, p) - div(rho/A*grad(p)), we are solving for mass flux, which satisfies continuity equation.

Another words:
- diffusion equation - correction to mass fluxes (to satisfy continuity) - phi+=pEqn.flux()
- convection-diffusion - mass fluxes, which continuity - phi=pEqn.flux()

I hope, this helps you. I'm really sorry for late post
mkraposhin is offline   Reply With Quote

Old   June 25, 2013, 08:40
Default please would you guide me in running a new application on OpenFOAM
  #23
Member
 
Anil Kunwar
Join Date: Jun 2013
Posts: 64
Rep Power: 11
Annier is an unknown quantity at this point
i am new to OpenFOAM.
i was going through the "OpenFOAM Programming Tutorial" written by Tommaso Lucchini. i modified icoFoam to icoScalarTransportFoam and cavity to cavityScalarTransport in accordance to the directions of the notes.
now i cannot set up the case cavityScalarTransport and cannot run it. would you please guide me with the commands for running this new application.thanking you in advance.

Last edited by Annier; July 23, 2013 at 02:03.
Annier is offline   Reply With Quote

Reply


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
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 11:16
Unknown error sivakumar OpenFOAM Pre-Processing 9 September 9, 2008 12:53
IcoFoam parallel woes msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 02:58
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 18:07


All times are GMT -4. The time now is 12:45.