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

Wall Heat Transfer Coefficient

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 12, 2013, 09:00
Smile Wall Heat Transfer Coefficient
  #1
Member
 
sunil
Join Date: Jul 2012
Location: Bangalore
Posts: 89
Rep Power: 5
sunilpatil is on a distinguished road
Hello sir,
I want to write CEL Expression for wall heat transfer Coefficient to calculate
wall heat flux (Q) but in my problem wall is at middle of an encloser i want to calculate Q for both sides of wall how to specify particular surface to calculate
Wall Heat Flux (Q) in CFX.
Thank you sir.
sunilpatil is offline   Reply With Quote

Old   March 12, 2013, 09:46
Default
  #2
Senior Member
 
RicochetJ's Avatar
 
Mr CFD
Join Date: Jun 2012
Location: Britain
Posts: 290
Rep Power: 6
RicochetJ is on a distinguished road
Hi, post an image of your problem please.

If you're going to deduct wall heat transfer coefficient then I believe (one of the more experienced CFD engineers can correct me on this) you must have adequate refinement at the wall in order to resolve the thermal boundary layer, which is usually smaller than a viscous boundary layer!
RicochetJ is online now   Reply With Quote

Old   March 12, 2013, 11:17
Smile Wall Heat Transfer Coefficient
  #3
Member
 
sunil
Join Date: Jul 2012
Location: Bangalore
Posts: 89
Rep Power: 5
sunilpatil is on a distinguished road
Hello Sir,
Thank You for your Reply
I uploaded image (http://s8.postimage.org/vkixp5sxh/CFD.jpg)
i want to calculate heat transfer coefficient at wall side 1 and side 2 and also heat transfer rate if we subject wall for different temperature conditions or varying Temperature
Thank you sir.
sunilpatil is offline   Reply With Quote

Old   March 12, 2013, 12:45
Default
  #4
Senior Member
 
RicochetJ's Avatar
 
Mr CFD
Join Date: Jun 2012
Location: Britain
Posts: 290
Rep Power: 6
RicochetJ is on a distinguished road
Hi,

Please describe:
1. What your boundary conditions are.
2. Working fluid (water, air, or other).

It looks like a simple problem but without more thorough information I can't be of any help.
RicochetJ is online now   Reply With Quote

Old   March 12, 2013, 18:18
Default
  #5
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,823
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Are you simulating this as a conjugate heat transfer simulation? That is, including heat transfer in the wall?
ghorrocks is offline   Reply With Quote

Old   March 13, 2013, 07:44
Smile Wall Heat Transfer Coefficient
  #6
Member
 
sunil
Join Date: Jul 2012
Location: Bangalore
Posts: 89
Rep Power: 5
sunilpatil is on a distinguished road
Hello sir,
Thank you for your quick reply
i am simulating this as a conjugate heat transfer problem
Boundary conditions are
1.Varying Temperature With Time To middle Wall
2.Material Working Medium-air at 25 C , Wall = Copper
3.All other walls are adiabatic
Thank You
sunilpatil is offline   Reply With Quote

Old   March 13, 2013, 17:29
Default
  #7
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,823
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
What do you mean by "varying temperature with time to middle wall".
ghorrocks is offline   Reply With Quote

Old   March 14, 2013, 01:24
Smile Varying Wall Temperature
  #8
Member
 
sunil
Join Date: Jul 2012
Location: Bangalore
Posts: 89
Rep Power: 5
sunilpatil is on a distinguished road
Hello sir,
I am applying This(http://s23.postimage.org/plc9nhfcb/cfd.jpg) type boundary
condition to Middle Wall

In that
x-axis Time in Seconds
Y-axis Temperature in Kelvin
(all this for transient case)
Thank you sir
sunilpatil is offline   Reply With Quote

Old   March 14, 2013, 06:28
Default
  #9
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,823
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
If you already know the temperature of the middle wall then why are you simulating the middle wall as a CHT solid? Just impose your temperature function as a temperature boundary and nothing else is required.
ghorrocks is offline   Reply With Quote

Reply

Tags
htc, wall heat transfer

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
Wall Transfer Coefficien - Heat Transfer Coefficient - CFX Gargioni CFX 9 April 15, 2013 07:46
wall heat transfer coefficient elsa CFX 1 March 23, 2010 06:28
Wall heat transfer coefficient (HTC) problem Mohamed khamis CFX 1 January 16, 2010 00:12
CFX wall heat transfer coefficient mactech001 CFX 1 January 5, 2010 22:33
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 16:55


All times are GMT -4. The time now is 10:14.