CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Energy conservation issue

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

LinkBack Thread Tools Display Modes
Old   May 10, 2010, 01:05
Question Energy conservation issue
New Member
Join Date: Feb 2010
Posts: 11
Rep Power: 9
izumi11 is on a distinguished road
Hi everyone I have a simple problem which I hope some of the geniuses on this forum could help me with..
I am simulating a vessel with an internal heat source and autothermal heat exchange between the incoming and outgoing fluid (air). The exchanger is a simple coil with air flowing around it. The walls are meshed with shell elements.
My problem is the following:
The energy balance is not conserved. I have air coming in at 300K and going out at no more than 400K. The inlet flow rate is 2e-6kg/s and internal power source is 5W. That gives a theoretical adiabatic temperature increase of well over 2000K, but it is not realized in my simulation.
I use DO radiation model with 0 absorptivity for air. All walls have an emissivity of 0.14. And external walls are adiabatic.

Any help is greatly appreciated!
izumi11 is offline   Reply With Quote


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
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
Maths problem when deriving conservation of energy equations. Demonwolf Main CFD Forum 1 June 15, 2009 14:21
The energy conservation in a case of phase change robin Phoenics 2 April 6, 2002 00:09
ENERGY CONSERVATION SCHEMES! Science Seeker Main CFD Forum 1 May 24, 2001 12:13
Energy Conservation Schemes! Science Seeker Main CFD Forum 0 May 21, 2001 03:31

All times are GMT -4. The time now is 11:27.