CFD Online Logo CFD Online URL
Home > Forums > CFX

Interface heat or temperature increase

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

LinkBack Thread Tools Display Modes
Old   October 2, 2013, 09:48
Default Interface heat or temperature increase
Senior Member
Join Date: Jul 2009
Posts: 451
Rep Power: 14
siw will become famous soon enough

I'm modelling an airflow through a system and part of this includes the air flowing through a heater (e.g. a car radiator geometry but heats the air rather than cools). The heater geometry is too complex to model explicitly as it is made up of many small hot water pipes and fins which imparts heat to the airflow. The goemetry also causes a pressure drop, much like a porous domain.

I don't have a flow rate vs pressure drop curve for the heater so I cannot determine the coefficients needed for a porous domain. Instead I thought to use an interface with an interface model with a negative pressure change to account for the pressure drop without having to include any subdomain or geometry. Also I have the pressure drop value at the design flow rate for this.

But the only thermal data I have is the heat transfer coefficient and the design air heater inlet and outlet temperatures and I don't see where this can be used with the interface. I thought about using a subdomain just so that I can add an energy source but without a momentum source for the pressure drop, for reason explained above.

Are there any recommendations to model this addition of heat and pressure drop to the airflow?

siw is offline   Reply With Quote

Old   October 2, 2013, 13:24
Senior Member
Edmund Singer P.E.
Join Date: Aug 2010
Location: Minneapolis, MN
Posts: 501
Rep Power: 11
singer1812 is on a distinguished road
What is to recommend? You are hosed with the Pdrop, you need one more point without making some gross assumptions.

I assume you have only h and dT for only that one point also? You need a bit more information than that.

I suppose you could assume h=f(V^1/2). You can replace the 1/2 by whatever value you wish (tube in cross flow perhaps will give you that exponent vs Re, with values ranging from 0.3-0.8).
singer1812 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
convergenceof natural convection prob. in cfx cpkewat CFX 15 January 31, 2014 07:29
CFX13 Post Periodic interface EtaEta CFX 7 December 8, 2011 18:15
Constant velocity of the material Sas CFX 15 July 13, 2010 08:56
Concentric tube heat exchanger (Air-Water) Young CFX 5 October 6, 2008 23:17

All times are GMT -4. The time now is 02:39.