UDF for thermal conductivity

ayoub1989 · January 15, 2014, 15:51

Dear Freinds...
i want to define thermal conductivity of nanofluid , I wrote UDF but when i interpreted to fluent, it show me a message "temp definition shadows previous definition" what's mean ?

PHP Code:


			
#include "udf.h"
#define k_np 40 /**thermal conductivity  for nanoparticle Al2O3******/
#define FI 0.02 /************volume fraction**************************/
DEFINE_PROPERTY(nanofluid_Conductivity,c,t)
{
real k_f;       /***thermal conductivity for fluid(water)***********/
real k_nf;      /******thermal conductivity  for nanofluid*********/
real temp = C_T(c,t); /****temperature******/
k_f= -0.000008 * (temp * temp) + ((0.0062 * temp) - 0.5388); 
k_nf = (((k_np + (2 * k_f) - (2 * (k_f - k_np)) * FI)/(k_np + (2 * k_f) + (k_f - k_np) * FI))) * k_f;
return k_nf;
}

Any help i will be grateful

pakk · January 16, 2014, 12:20

It means that the variable name "temp" is already in used somewhere else. Not in your file, but somewhere in Fluent's files.

This will probably not give a real problem, but to be sure, you could rename your variable name into something else.

ayoub1989 · January 16, 2014, 16:17

thank you

pakk , i renamed the variable and the UDF work without problem

thanks again

salehorafi · January 20, 2014, 12:08

did you use compile or interpret for the UDF? I'm trying to use UDF for properties in a similar case but didn't work with me

ayoub1989 · January 22, 2014, 04:46

Quote:

Originally Posted by salehorafi

did you use compile or interpret for the UDF? I'm trying to use UDF for properties in a similar case but didn't work with me

I used interpreted , compiled and the udf work perfectly

here's my email to contact me : ayoubbennia@gmail.com

ayoub1989 · August 18, 2014, 06:15

I used interpreted , compiled and the udf work perfectly

January 15, 2014, 15:51	UDF for thermal conductivity	#1
ayoub1989 New Member Bennia Ayoub Join Date: Dec 2013 Location: Algeria Posts: 6 Rep Power: 13	Dear Freinds... i want to define thermal conductivity of nanofluid , I wrote UDF but when i interpreted to fluent, it show me a message "temp definition shadows previous definition" what's mean ? PHP Code: #include "udf.h" #define k_np 40 /thermal conductivity for nanoparticle Al2O3**/ #define FI 0.02 /********volume fraction**********************/ DEFINE_PROPERTY(nanofluid_Conductivity,c,t) { real k_f; /thermal conductivity for fluid(water)********/ real k_nf; /**thermal conductivity for nanofluid*****/ real temp = C_T(c,t); /temperature***/ k_f= -0.000008 (temp * temp) + ((0.0062 * temp) - 0.5388); k_nf = (((k_np + (2 * k_f) - (2 * (k_f - k_np)) * FI)/(k_np + (2 * k_f) + (k_f - k_np) * FI))) * k_f; return k_nf; } Any help i will be grateful Last edited by ayoub1989; January 16, 2014 at 16:21.

January 16, 2014, 12:20		#2
pakk Senior Member Join Date: Nov 2013 Posts: 1,965 Rep Power: 27	It means that the variable name "temp" is already in used somewhere else. Not in your file, but somewhere in Fluent's files. This will probably not give a real problem, but to be sure, you could rename your variable name into something else. ayoub1989 likes this.

January 20, 2014, 12:08	Nanofluid properties	#4
salehorafi New Member Join Date: May 2013 Posts: 4 Rep Power: 13	did you use compile or interpret for the UDF? I'm trying to use UDF for properties in a similar case but didn't work with me

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January 16, 2014, 16:17		#3
ayoub1989 New Member Bennia Ayoub Join Date: Dec 2013 Location: Algeria Posts: 6 Rep Power: 13	thank you pakk , i renamed the variable and the UDF work without problem thanks again

August 18, 2014, 06:15		#6
ayoub1989 New Member Bennia Ayoub Join Date: Dec 2013 Location: Algeria Posts: 6 Rep Power: 13	I used interpreted , compiled and the udf work perfectly