# Accessing C_mu within UDF

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

 July 3, 2014, 04:26 Accessing C_mu within UDF #1 New Member   Jack Chilvers Join Date: Dec 2013 Location: St Neots, Cambridgeshire Posts: 12 Rep Power: 5 Dear All, I would like to access the parameter C for use within a Fluent UDF. To this end, could somebody please tell me the variable name such that: cmu = (cell_index, cell_thread); Many thanks, Jack

 July 3, 2014, 06:48 #2 New Member   Manuel Join Date: Jan 2014 Posts: 18 Rep Power: 5 Well, maybe you can compute from its definition. But I don't know if you can access the viscous turbulence if you're not using Spalart-Allmaras. Maybe this works: (Cmu=turb.visc / density / K^2 * epsilon ) Code: cmu=C_NUT(c,t)/C_R(c,t)/C_K(c,t)/C_K(c,t)*C_D(c,t);

 July 3, 2014, 10:14 #3 Senior Member   Join Date: Nov 2013 Posts: 1,107 Rep Power: 15 Don't you mean C_MU_L(c,t)?

 July 3, 2014, 11:31 #4 New Member   Manuel Join Date: Jan 2014 Posts: 18 Rep Power: 5 I have had a better look to the manual and saw that the turbulence eddy viscosity is given by C_MU_T(c,t). So I correct what I said in previous post, you may compute c_mu as: cmu=C_MU_T(c,t)/C_R(c,t)/C_K(c,t)/C_K(c,t)*C_D(c,t); But I wonder... don't you set this parameter as a constant in the turbulence model panel? Why do you need to find it for a specific cell?

 July 19, 2017, 12:12 CMU access macro #5 Member   Vedamt Chittlangia Join Date: Feb 2016 Posts: 64 Rep Power: 2 CMU is defined as constant in GUI panel so you can directly put its value in the UDF. I want to modify CMU value as a local variable. I could not find any macro to do this so I used DEFINE_TURBULENT_VISCOSITY() and put my CMU definition there. But the problem seems that this does not suppress the CMU value that is already present in the viscous dialog box of GUI panel. Can someone help me? Thanks

 Tags fluent, udf

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Dushan FLUENT 1 April 22, 2017 21:05 ral007 Fluent UDF and Scheme Programming 1 October 14, 2015 09:21 pmtgt Fluent Multiphase 2 December 4, 2013 07:10 aditya.pandare Fluent UDF and Scheme Programming 9 March 21, 2013 00:38 argeus FLUENT 2 February 9, 2011 05:08

All times are GMT -4. The time now is 22:39.