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

Effective thermal conductivity UDF - C_K_EFF??

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 9, 2004, 19:43
Default Effective thermal conductivity UDF - C_K_EFF??
  #1
Craig
Guest
 
Posts: n/a
Hi, I am modeling heat transfer in a porous media and get a parse error when I work with the macro C_K_EFF. I get a parse error in that line. If I replace with any other arbitrary macro, say C_K_L or C_MU_EFF or whatever I want it compiles fine. Using V6.1.

Anybody have any ideas why this doesn't work? My UDF is below.

#include "udf.h"

DEFINE_PROPERTY(cell_conductivity, cell, thread) { real k_s; real rho = C_R(cell, thread); real u = C_U(cell, thread); real v = C_V(cell, thread); real mu = C_MU_L(cell, thread); real k_gas = C_K_EFF(cell, thread);

k_s=1.613*(4.62+.0001425*rho/mu*sqrt(u*u+v*v))*k_gas;

return k_s; }
  Reply With Quote

Old   February 10, 2004, 05:14
Default Re: Effective thermal conductivity UDF - C_K_EFF??
  #2
Rob Hart
Guest
 
Posts: n/a
works fine in 6.0.20 here.

If you are feeling adventurous, you could have a browse through udf.h and see how C_K_EFF is defined.

In my #define udf.h C_K_EFF is:

#define C_K_EFF(c,t)(C_K_L(c,t) + C_K_T(c,t))

You already said C_K_L works. What about C_K_T?

Rob

  Reply With Quote

Old   February 10, 2004, 19:20
Default Re: Effective thermal conductivity UDF - C_K_EFF??
  #3
Craig
Guest
 
Posts: n/a
Thanks, actually C_K_T doesn't work either, probably because I'm not even using a turbulence model (I was confused - I didn't want K_EFF, I thought that referred to the effective conductivity of a porous medium).
However I do have another problem, I'm sure this must be something really simple I'm missing, I can't seem to load in more than 2 UDFs at once. If I try to interpret a second UDF, the first one is eliminated from the model. What do I need to do?
Thanks, much appreciated
  Reply With Quote

Old   February 10, 2004, 19:54
Default Re: Effective thermal conductivity UDF - C_K_EFF??
  #4
Rob Hart
Guest
 
Posts: n/a
Well the obvious thing to do is put them all in one file.

To be honest I've never tried to have more than one .c file in a case.

Rob
  Reply With Quote

Old   February 11, 2004, 15:02
Default Thank you Rob
  #5
Craig
Guest
 
Posts: n/a
Ahh, that was the simple thing that I was missing. Seems obvious to me now. Thanks for your help.
  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
I need one simple udf code for effective thermal conductivity of nanofluid mvf Fluent UDF and Scheme Programming 0 July 11, 2010 10:23
UDF for effective thermal conductivity Rashmi FLUENT 1 November 6, 2007 21:08
UDF for effective thermal conductivity Mona FLUENT 2 January 16, 2006 14:36
Can wemodify effective thermal conductivity by UDF FengYun FLUENT 2 October 27, 2005 06:28
Porous Media Effective Thermal Conductivity Greg Perkins FLUENT 3 August 5, 2001 22:53


All times are GMT -4. The time now is 20:28.