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

goddamnit: how to set up heat transfer from fluid to solid

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 13, 2012, 10:58
Default goddamnit: how to set up heat transfer from fluid to solid
  #1
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Canada
Posts: 392
Rep Power: 17
macfly is on a distinguished road
Hi all,

I can't find how to properly set up basic heat transfer from a fluid to a solid. Here's what I've done so far:

In Gambit:
- create 2 adjacent faces
- connect the 2 adjacent edges into only 1
- specify continuum types to solid face and fluid face
- specify boundary conditions, the merged edge between solid and fluid is specified as wall

In Fluent:
- Fluent automatically created wall and wall-shadow for the fluid-solid boundary and the thermal boundary condition is set to coupled.
- No error messages, check case, everything seems ok.

Looked at attached jpg, the cold solid never heats up, instead, it lowers the temperature of the fluid along the fluid-solid boundary.

Quick help or redirection towards a tutorial that I don't know the existence of would be very appreciated. Thanks.
Attached Images
File Type: jpg 1.jpg (63.1 KB, 48 views)
macfly is offline   Reply With Quote

Old   June 13, 2012, 12:15
Default
  #2
New Member
 
Join Date: Aug 2011
Posts: 9
Rep Power: 14
krisshoe is on a distinguished road
Try adjusting the range of temperature contours that you are plotting to something like 300-330K to capture the contours in the solid.
krisshoe is offline   Reply With Quote

Old   June 13, 2012, 19:25
Default
  #3
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Canada
Posts: 392
Rep Power: 17
macfly is on a distinguished road
Hi krisshoe, in my first post/first figure, the solid is entirely at 300 K, no matter how I refine the temperature contours.

Here's another result : the bottom boundary is set to symmetry (or wall with 0 heat flux) instead of fixing its temperature at 300 K. Temperature of solid is initialized at 300 K. The solid heats up, this is good news, but the results are still incoherent : it's a steady-state simulation --> the solid should end up at 1000 K.
Attached Images
File Type: jpg 2.jpg (37.4 KB, 24 views)

Last edited by macfly; June 15, 2012 at 09:59.
macfly is offline   Reply With Quote

Old   June 15, 2012, 09:51
Default
  #4
Member
 
Robert
Join Date: Mar 2011
Location: Warsaw
Posts: 62
Rep Power: 15
Kwiaci is on a distinguished road
Is this steady state or transient simulation? From what material is your wall? Do your results vary when you change number of iterations?
Kwiaci is offline   Reply With Quote

Old   June 15, 2012, 10:13
Default
  #5
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Canada
Posts: 392
Rep Power: 17
macfly is on a distinguished road
Hi Kwiaci,

1. Steady-state simulation
2. Wall material is copper from Fluent material database
2. I set 500 iterations but the solution is converged after 33 iterations.

Physically, I think that the solid should end up at 1000 K in a steady-state simulation. But I'm a little confused about how to verify by calculations on paper. Also, I don't understand why we have to initialize a steady-state simulation?
macfly is offline   Reply With Quote

Old   June 16, 2012, 07:07
Default
  #6
Member
 
Robert
Join Date: Mar 2011
Location: Warsaw
Posts: 62
Rep Power: 15
Kwiaci is on a distinguished road
To verify your simulation on the paper extract heat transfer coefficient from inner wall so you can asses inner wall temperature and then use equations from for example: http://www.wlv.com/products/databook/ch1_1.pdf

Can you write what are dimensions of your pipe (it looks like a very thin pipe).
Kwiaci is offline   Reply With Quote

Old   June 16, 2012, 10:40
Default
  #7
Senior Member
 
François Grégoire
Join Date: Jan 2010
Location: Canada
Posts: 392
Rep Power: 17
macfly is on a distinguished road
Pipe has a radius of 0.1 m.

I'll see what calculations I perform, I think it should be pretty simple actually. Thanks for the nice basic résumé.
Attached Images
File Type: jpg 3.jpg (34.1 KB, 17 views)
macfly is offline   Reply With Quote

Old   June 16, 2012, 12:50
Default
  #8
Member
 
Robert
Join Date: Mar 2011
Location: Warsaw
Posts: 62
Rep Power: 15
Kwiaci is on a distinguished road
One thing more: I would use axis instead of symmetry because now you simulate flow in a rectangular infinite channel. Using axis you will get logarithmic temperature distribution like in pipe - now you have linear distribution.
Kwiaci is offline   Reply With Quote

Reply

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
Solid / Fluid Heat Transfer Koranten FLUENT 3 March 19, 2011 08:21
heat transfer between solid and fluid Devy FLUENT 4 June 4, 2010 01:28
No results for solid domain Gary Holland CFX 10 March 13, 2009 04:30
How can I increase Heat Transfer at Domain Interf? B.Simon CFX 3 October 28, 2008 19:53
Concentric tube heat exchanger (Air-Water) Young CFX 5 October 7, 2008 00:17


All times are GMT -4. The time now is 08:40.