Cell Variable Macro Names (C_x_x...) for UDFs

meangreen · July 8, 2015, 20:18

Hi All,

I am trying to write several UDFs and I found there is a serious lack of "cell variable macro names" in the UDF manuals (and almost anywhere I can look). For example, a cell variable for x-velocity is C_U(c,t). I was hoping someone could help me with the following properties I want to pull OUT of fluent in order to write a UDF. I am using the Eulerian multiphase option.

The properties I am looking for currently are constants, I just want to make sure the UDF can take the information out of Fluent so the user doesn't have to go in and change the UDF every time they want to run a different particle type (i.e. I want it idiot proof).

1. Particle diameter
2. Coefficient of Restitution

I would be happy to start compiling a list of cell variable macro names and posting on updating on the forum.

I have found the granular temperature is C_GT(c,t).

Thanks!

marialhm · January 17, 2016, 05:48

Hey, do you know how to get the size of the cell using udf, like the length and the width of the cell, if in a 2d simulation. thanks.

Sachin Zanje · January 15, 2021, 01:48

There is no macro available for calculating length and width of cell in fluent.

AlexanderZ · January 15, 2021, 03:44

there are macros to get faces area of cell:
F_AREA_2D_X(f,t)
F_AREA_2D_Y(f,t)
F_AREA_2D_Z(f,t)
from this you can calculate length and width
C_VOLUME(c,t) gives you a volume of cell

July 8, 2015, 20:18	Cell Variable Macro Names (C_x_x...) for UDFs	#1
meangreen Member Casey Join Date: Jun 2009 Posts: 98 Rep Power: 16	Hi All, I am trying to write several UDFs and I found there is a serious lack of "cell variable macro names" in the UDF manuals (and almost anywhere I can look). For example, a cell variable for x-velocity is C_U(c,t). I was hoping someone could help me with the following properties I want to pull OUT of fluent in order to write a UDF. I am using the Eulerian multiphase option. The properties I am looking for currently are constants, I just want to make sure the UDF can take the information out of Fluent so the user doesn't have to go in and change the UDF every time they want to run a different particle type (i.e. I want it idiot proof). 1. Particle diameter 2. Coefficient of Restitution I would be happy to start compiling a list of cell variable macro names and posting on updating on the forum. I have found the granular temperature is C_GT(c,t). Thanks!

January 17, 2016, 05:48		#2
marialhm Member Maria Join Date: Jul 2013 Posts: 84 Rep Power: 12	Hey, do you know how to get the size of the cell using udf, like the length and the width of the cell, if in a 2d simulation. thanks. Sachin Zanje likes this.

January 15, 2021, 03:44		#4
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	there are macros to get faces area of cell: F_AREA_2D_X(f,t) F_AREA_2D_Y(f,t) F_AREA_2D_Z(f,t) from this you can calculate length and width C_VOLUME(c,t) gives you a volume of cell __________________ best regards ****************************** press LIKE if this message was helpful

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
emag beta feature: charge density	charlotte	CFX	4	March 22, 2011 09:14
Cell ID macro ?!?!?!?!?!	bohis	FLUENT	1	November 14, 2008 08:26
How to pass a variable from a define macro...	Padian	FLUENT	2	May 30, 2008 05:22
field variable macro of the mean-x-velocity?	zt xie	FLUENT	2	November 15, 2005 05:48
Macro for velocity on the face of the cell	Dragos	FLUENT	0	April 7, 2005 11:12

January 15, 2021, 01:48		#3
Sachin Zanje New Member Maharashtra Join Date: Dec 2017 Posts: 13 Rep Power: 8	There is no macro available for calculating length and width of cell in fluent.