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

Inconsistent Total Heat Transfer Rate

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 24, 2007, 11:04
Default Inconsistent Total Heat Transfer Rate
  #1
Ken Adams
Guest
 
Posts: n/a
Hello all,

I modeled a steady-state natural convection problem involving a heatsink and surrounding air using segregated solver. After residuals converged, I checked Flux Reports. Mass Flow Rate over the boundaries of the air domain was to the order of 10e-4, which makes sense. Total Heat Transfer Rate over all the boundaries of the heatsink is around 4W, which does not seem right, compared with the total input power of 23W. However, the total heat transfer rate calculated by Surface Integrals gives 0.2W. Could anyone explain what may cause the inconsistency? I read in Fluent 6.2 manual that Flux Reports gives more accurate results than Surface Integrals. So does that mean there is something wrong with the simulation? Some information of the model is listed below:

1. Segregated solver. Steady-state

2. Discretization scheme: Body Force Weighted for Pressure. Second Order Upwind for Density, Momentum, and Energy.

3. Ideal gas model for air and pressure inlet and pressure outlet on the boudaries of the air domain.

4. Simulation was iterated with Fluent 6.2 for 3,000 times. Residuals and total heat transfer rate over all surfaces were monitored. After all iterations, all residuals converged and total heat transfer rate leveled off.

Thanks in advance,

Ken
  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
Heat transfer (conduction) between two pipes shields FLUENT 13 October 14, 2012 15:44
MRF and Heat transfer calculation Susan YU FLUENT 0 June 2, 2010 08:46
heat tansfer rate and mass transfer rate Ryan FLUENT 0 June 29, 2007 11:13
total pressure influence on heat transfer fab Main CFD Forum 8 May 19, 2005 09:24
Turbulent wall heat transfer rate? Tom Main CFD Forum 1 March 1, 2001 06:51


All times are GMT -4. The time now is 21:33.