CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Fluent UDF and Scheme Programming

UDF for modelling heat loss in 2D

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 18, 2010, 01:54
Default UDF for modelling heat loss in 2D
  #1
New Member
 
Shrinand Iyer
Join Date: Jun 2010
Posts: 5
Rep Power: 8
Shrinand is on a distinguished road
HI. I need help on how to construct a UDF, which can account for heat loss in a 2D channel. Thus effectively it will model 3D results from the 2D.

More details-http://FastFreeFileHosting.com/file/40127/UDf-bmp.html

Last edited by Shrinand; June 18, 2010 at 02:14.
Shrinand is offline   Reply With Quote

Old   February 29, 2016, 06:47
Default heat loss through walls
  #2
New Member
 
s.p.gupta
Join Date: Dec 2015
Posts: 3
Rep Power: 2
shri2802 is on a distinguished road
#include "udf.h"
#include "math.h"
#include "sg.h"

DEFINE_PROFILE(HTCh, t, i)
{
face_t f;
Thread *tco;
cell_t co; /**thread data**/
real Tc=0; /**centraoid temperature of cells **/
real Ts2=0; /** secondary side temperature for Grashof no **/
real q=0; /** heat flux at face **/
begin_f_loop(f, t)
{
Ts = F_T(f,t);
co =F_C0(f,t);
tco=THREAD_T0(t);
Tc=C_T(co,tco);
BOUNDARY_FACE_GEOMETRY(f,t,A,ds,es,A_by_es,dr0);
area = sqrt(A[0]*A[0]+A[1]*A[1]+A[2]*A[2]);
theta=area/A_by_es;

q=kl*abs(cos(theta))*(Tc-Ts)/ds;

Ts2=Ts-(log(d/di)*q*di/(2*ki)); //for cylinder
// Ts2=Ts- abs(dt*q/ki); // for rectangular slab
shri2802 is offline   Reply With Quote

Old   February 29, 2016, 06:50
Default
  #3
New Member
 
s.p.gupta
Join Date: Dec 2015
Posts: 3
Rep Power: 2
shri2802 is on a distinguished road
This code will work better at solid meshed surface, but if u wish to use if fluid region you have to consider convective and transient energy terms too.
"Ts2" will give insulated body temperature, if u don't have insulation you can use directly "Ts" to calculate Gr number and using that u can relate with heat transfer coefficients.

Last edited by shri2802; March 3, 2016 at 07:25.
shri2802 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
UDF for wall heat flux ? Seyoung Oh FLUENT 5 September 15, 2016 11:14
Problem of heat balance in Coal Boiler simulation DG FLUENT 9 December 25, 2008 21:57
how to impose experimental dat as boundary conditi Rogerio Fernandes Brito FLUENT 14 November 25, 2008 06:47
Specific Heat (Cp) cannot be calculated by UDF??? JoĆ£o Fernandes FLUENT 0 October 16, 2008 18:58
UDF convective heat transfer correlations sarah FLUENT 0 March 29, 2007 09:52


All times are GMT -4. The time now is 11:42.