[marye]

Hi,
I have another problem...
Just to try, I wanted to put different viscosities to the pair cells and impair cells...

#include"udf.h"
DEFINE_PROPERTY(cell_viscosity, cell, thread)
{
real mu_lam;
cell_t c;
int i;
for (i=1, i<200, i++)
if ((cell_t ci %2)==0)
mu_lam = 2.;
else
mu_lam = 1.;
return mu_lam;
}

But it doesn't work... I'm new with both Fluent and C++...

If anyone could help..
Thanks!!

[Chris D]

One thing that I noticed is that the for loop should be

for (i = 1; i < 200; i++)

Use a semicolon to separate arguments, not a comma. Also, I don't think that

if ((cell_t ci %2)==0)

will do what you think it will do. ci is a new variable of type cell_t, it's not cell_t c at index i. Are you trying to loop over the cells in a domain? I think there are macros to do that for you. (I have some c++ experience, but not really any experience writing UDFs, so I'm exactly sure how to do that.) One final thing is that UDF's are supposed to be written in c, not c++.

[marye]

thank you for your answer!

ok then, C and not C++

I'll try ";" instead of ","

I'm trying to do : All the cells at index i pair have viscosity1
All the cells at index i impair have viscosity 2

I have no experience both in writting C and UDFs so I don´t know very well the macros...

[Chris D]

Section 3.3 in the UDF manual is about looping macros.

[marye]

Yes, I will see that again... I must have forgotten something...

Thank you for your help!