CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > FloEFD, FloWorks & FloTHERM

Specifying turbulence parameters for natural convection on vertical flat plate

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 12, 2013, 12:22
Smile Specifying turbulence parameters for natural convection on vertical flat plate
New Member
Join Date: Nov 2010
Posts: 4
Rep Power: 15
abu250feldman is on a distinguished road
Hi all,
I am simulating natural convection from vertical wall. the fluid is water.
I know this is very easy to calculate using simple correlations, however for some reason, I got more then 50% error between the manually calculated and CFD results. I have a wall 2.4 m high with Tinf=10 C and DT of 20 C. The Ra_L is turbulent (equal 5e12). I used two correlations for turbulent flow 1. 0.1*Ra^1/3 and 2. (0.825+0.387*Ra^(1/6)...)^2 (churchill and cho). I got h=450 W/m^K and h=534 W/m^K respectively.

In the CFD however, I get 340 W/m^K when using the "turbulence intensity and length" with default parameters. when I change to "Turbulence energy and dissipation" I get 400 W/m^K. Both results are way off...
I can get different results if I change the parameters but its is difficult to know the correct values.

My question is (finally): which model is better for natural convection (my case) and does anyone (Boris maybe?) has some guidelines on specifying the correct turbulence parameters?

Thanks in advance
abu250feldman is offline   Reply With Quote

Old   December 20, 2013, 09:01
Join Date: Jul 2009
Posts: 616
Rep Power: 23
Boris_M will become famous soon enough
Hi Yoav,

this is a validation case the developers are considering with each version before shipment.
In fact I have the project setup and can send you the results if you provide me with your email address in a private message.

Regards and happy holidays,
Boris_M is offline   Reply With Quote

Old   May 5, 2014, 13:42
Senior Member
Join Date: Feb 2012
Location: Canada
Posts: 111
Rep Power: 14
enayath is on a distinguished road

Could you please share this information with me also?
I sent my email address in a private message.

Thank you,

Last edited by enayath; May 23, 2014 at 11:40.
enayath is offline   Reply With Quote


natural convection, turbulence parameters

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
drag of flat plate with cavity Far FLUENT 0 May 18, 2010 04:57
DNS for Impinging Jet on a Flat Plate Chandra Shekhar Main CFD Forum 3 January 18, 2010 05:03
Discussion: Reason of Turbulence!! Wen Long Main CFD Forum 3 May 15, 2009 09:52
Seperated Flow and Turbulence modelling flat plate Simon Mizzi Main CFD Forum 1 December 16, 2003 01:26
Turbulence dead? well... can somebody help me with a flat plate meanwhile? Javier Main CFD Forum 2 May 23, 2000 04:41

All times are GMT -4. The time now is 12:32.