CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Phoenics

heat extraction

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

LinkBack Thread Tools Search this Thread Display Modes
Old   November 14, 2002, 07:28
Default heat extraction
M. Pijnenborg
Posts: n/a
Hi folks,

I would like to implement a negative heat flux into my model. So far I have done several test with a blockage domain fluid and a plate. For both cases negative and positive heat fluxes are tested, none of the cases showed any effects. I am using the Extended Simple Chemical Reacting System (7-gas model), this might influences the heat fluxes.

Anybody any suggestions???


  Reply With Quote

Old   November 15, 2002, 08:00
Default Re: heat extraction
Posts: n/a

First of all, try to isolate more closely the potential problem. The 7-gas issue is likely to be irrelevant

Therefore, I would recommend your to test your "negative heat flux" on a case with a constant-property-fluid material (air at 20C for instance), on a geometry that you should keep as simple as possible (2D typically).

If the problem persues, then you'll be in a position of identyfing more precisely what goes wrong.


  Reply With Quote

Old   November 17, 2002, 20:51
Default Re: heat extraction
Posts: n/a

I use Pv3.4 with bloackages in the domain with a positive heat flux alot.

A few things that I use when toble shooting.

Check if the heat flux is set as per unit volume or by 'abosulte value' - tag in the vr editor setting (I think these are the words).

Try setting the heat flux to some mucher larger - 10 to 100 time what you are looking at. It may juct be that at the heat flux levels you are talking about are too small to have a significant impact on the model.

Hope this helps.


  Reply With Quote

Old   November 18, 2002, 06:06
Default Re: heat extraction
Mark Russell
Posts: n/a
Completely concur with the above posts.

To gain confidence with Phoenics, and indeed any CFD, test the configuration in stages. Set up a simplified case that allows you to see if you have implemented the conditions correctly. In addition to the '2d' and 'large value' suggestions you could also try to solve a diffusion only problem - that way you should be able to see the heat being drawn into the heat sink from the rest of the material. It might be, as implied, that the value of heat sink is so small that convection effects are dominating and that you simply cant see it.

Hoping that this helps and that 'grandmother and eggs' doesn't spring to mind.

Mark Russell
  Reply With Quote


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
How to model heat extraction device? i.e CRAC Unit laisquared FLUENT 0 January 1, 2009 23:07
FX Feature Extraction bastil OpenFOAM Post-Processing 3 December 15, 2008 09:18
[OpenFOAM] Data extraction xy plot atzaru ParaView 3 January 28, 2006 17:18
Data extraction Renaud CFX 0 February 4, 2003 06:04

All times are GMT -4. The time now is 18:43.