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

Thin wall vs Solid wall in Heat Transfer problem?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 1, 2012, 16:27
Question Thin wall vs Solid wall in Heat Transfer problem?
  #1
New Member
 
Kristofer Rasmusson
Join Date: Sep 2012
Posts: 5
Rep Power: 4
Kristofer. is on a distinguished road
Hi!

Im doing a master thesis where Im simulating the following simple case (it will be more complicated later on, when I get this case to work properly):


-A small (50x50x50mm) hollow box
-5 mm above that a sun-protecting thin plate
-surrounding (and inside the box) fluid is air (v=0.5 m/s)
-and I've applied the solar ray tracing.


The most important output is the temperature on and inside the box, which right now as I simulate doesnt change at all, the plate is absorbing all the heat.

Ive done many tutorials on heat transfer (natural convection, different radiation models etc.) but I still have some questions:

-Should I do the geometry on the plate (and the box) as a thin wall or should I mesh like the real geometry? Big differences on computational efforts?

-Why isnt the temperature on the box changing at all? The heat from the plate should have some impact on the box, even if it is opaque?

-The energy-residual goes down the first 100-200 iterations but its constant after that (10e-05 to 10e-06 depending on different things), and as long as I continue calculation the plate gets hotter and hotter, any advice on finding equilibrium with the solar ray tracing? Maybe I should do calculations overnight?


If you could help me with any of these questions, I owe you a beer!

Kris
Kristofer. is offline   Reply With Quote

Old   October 5, 2012, 05:37
Default
  #2
New Member
 
Kristiano Gomez
Join Date: Oct 2012
Posts: 1
Rep Power: 0
Brazil_Lazzarini is on a distinguished road
are u using solar ray tracing or DO-irradiation? I think it depends. If you have thin wall you should activate the shell conduction. This is what i found out when i tried to simulate automobile-sun-heating but then i gave up because it seemed impossible. would also appreciate som help with the solar load model!
Brazil_Lazzarini is offline   Reply With Quote

Reply

Tags
conve, fluent, heat transfer, solar ray tracing

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
Two-sided Wall Heat Transfer BC - No Separate Solid Mesh and No Heat Transfer Coeff swahono OpenFOAM Running, Solving & CFD 8 February 26, 2015 05:30
Solid to Fluid Heat Transfer Modelling Problem bortonj88 Main CFD Forum 3 November 14, 2011 15:21
unsteady heat transfer model problem Beryl FLUENT 0 July 12, 2011 23:26
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 16:55
Multicomponent fluid Andrea CFX 2 October 11, 2004 05:12


All times are GMT -4. The time now is 19:38.