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

Heat transfer coefficient at wall

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

Like Tree2Likes
  • 1 Post By oozcan
  • 1 Post By LuckyTran

Reply
 
LinkBack Thread Tools Display Modes
Old   March 24, 2017, 00:06
Default Heat transfer coefficient at wall
  #1
Member
 
Tleja
Join Date: Sep 2013
Posts: 36
Rep Power: 5
Tleja is on a distinguished road
Hi everyone

I'm working for gas-solid in fluidized bed reactor.

My system description, I packed solid at the buttom of reactor, then i feed gas throughout the reactor with 400K of temperature gas feed. I also kept the wall temperature as constant value of 350K.

The result from this system, I can get the realistic temperature profile of solid and gas.

As my knowledge, The wall heat flux at the wall should be calculated from

Q=hw(Twall-Tg)

Q= wall heat flux;
***hw= heat transfer coefficient;
Twall= temperature at wall;
Tg= Temperature of gas at the first layer of cell from wall;

Can anyone let me know how fluent calculate heat transfer coefficient of each phases at the wall??

Best regard
Tleja
Tleja is offline   Reply With Quote

Old   March 24, 2017, 02:40
Default
  #2
Senior Member
 
Onur zcan
Join Date: Feb 2016
Location: Istanbul/Turkey
Posts: 421
Rep Power: 5
oozcan is on a distinguished road
heat transfer made by conduction or convection are always equivalent (e.g. medium-solid, solid-fluid,solid-solid- fluid-fluid) . So,that is, you say ''at the wall''you can get only one heat transfer coeff. That is forced-convective heat transfer coeff. Moreover, I could not get Tg. How could you know that that temp. is first layer of cell from wall. You could just give your model boundary conditions and you could get results in compliance with your mesh. You could not know it which temperature gradient has in first layer cell from the wall. Moreover, the equation is to be solved in ANSYS-Mechanical in this way but not FLUENT.
Tleja likes this.
oozcan is offline   Reply With Quote

Old   March 26, 2017, 03:00
Default
  #3
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,821
Rep Power: 26
LuckyTran will become famous soon enoughLuckyTran will become famous soon enough
Quote:
Originally Posted by oozcan View Post
Moreover, I could not get Tg. How could you know that that temp. is first layer of cell from wall.
There is a variable called something like wall temperature which actually gives you the fluid temperature of wall adjacent cells.
Tleja likes this.
LuckyTran is offline   Reply With Quote

Old   March 27, 2017, 02:56
Default
  #4
Member
 
Tleja
Join Date: Sep 2013
Posts: 36
Rep Power: 5
Tleja is on a distinguished road
Thank you so much for your kindly help

At the moment, i found out how to calculate convection at the near wall in ANSYS theory as
HTML Code:
http://www.afs.enea.it/project/neptunius/docs/fluent/html/th/node99.htm#stdwf
This information is really good for me. I hope that will be useful for who is studying in heat transfer

Best regard
Tleja
Tleja is offline   Reply With Quote

Reply

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
How To Calculate Average Heat Transfer Coefficient in CFD-Post? Shomaz ul Haq CFX 4 May 3, 2016 21:14
Is it possible to set constant heat transfer coefficient at a wall? jpina CFX 6 March 30, 2016 15:49
Heat transfer coefficient near the wall in two phase flow XavierW Main CFD Forum 0 February 18, 2016 11:37
Thin Wall Heat Transfer BC for rhoSimpleFoam swahono OpenFOAM Running, Solving & CFD 12 October 4, 2013 11:49
Wall heat transfer coefficient (HTC) problem Mohamed khamis CFX 1 January 16, 2010 00:12


All times are GMT -4. The time now is 07:52.