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

Can wemodify effective thermal conductivity by UDF

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 26, 2005, 23:09
Default Can wemodify effective thermal conductivity by UDF
  #1
FengYun
Guest
 
Posts: n/a
In Phoenics CFD software, we can modify effecive thermal conductivity in energy equation by adjusting the thermal diffusivity. I want to know if we can do the same thing in FLUENT by UDF. The DEFINE_DIFFUSIVITY macro is not possible because it only can be used to specify the diffusivity for the species transport equations or user-defined scalar (UDS) transport equations.

Thanks a lot.
  Reply With Quote

Old   October 27, 2005, 01:54
Default Re: Can wemodify effective thermal conductivity by
  #2
RoM
Guest
 
Posts: n/a
Thermal diffusivity is modeled by

k+cp*turb_viscosity/Pr_Energy

k is conductivity and cp specfific heat. You can set Prandtl number in the viscous panel either as constant value or udf. Unfortunatly there is no documentation about the needed macro (only for TKE and TDR Prandtl). In udf.h you can find (beside the two DEFINE_PRANDTL macros mention in the udf guide) three macros

#define DEFINE_PRANDTL_O(name, c, t) real name(cell_t c, Thread *t)

#define DEFINE_PRANDTL_T(name, c, t) real name(cell_t c, Thread *t)

#define DEFINE_PRANDTL_T_WALL(name, c, t) real name(cell_t c, Thread *t)

Maybe one of those will work.

Good Luck

RoM
  Reply With Quote

Old   October 27, 2005, 05:28
Default Re: Can wemodify effective thermal conductivity by
  #3
FengYun
Guest
 
Posts: n/a
Rom, thank 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 09:23
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
Effective thermal conductivity UDF - C_K_EFF?? Craig FLUENT 4 February 11, 2004 15:02
Porous Media Effective Thermal Conductivity Greg Perkins FLUENT 3 August 5, 2001 21:53


All times are GMT -4. The time now is 06:05.