Hi all I read an example in the UDF manual as follow:

DEFINE_PRANDTL_K(user_pr_k,c,t) { real pr_k, alpha; real mu = C_MU_L(c,t); real mu_t = C_MU_T(c,t); alpha = rng_alpha(1., mu + mu_t, mu); pr_k = mu_t/((mu+mu_t)*alpha-mu); return pr_k; }

I couldn't find the definition of the funcion rng_alpha()in the manual. I could guess how does this function work, but I want to know how many else functions like this are there in fluent, and where to find the definitions of functions like this ?

Hi Lucy Have a look at the header files in the "src" directory of your Fluent installation for rng_alpha and you should get some hits. Maybe try mem.h first or search udf.h with all headers included there. Markus

Thanks Markus! I have read these header files and I found them very difficult to understand. They are written without notes. How do you get useful information from these header files? For example, the function "rng_alpha". How do you know its usage (its parameter and what it returns)since the header file "mem.h" doesn't explain it? Thank you very much for help!

Lucy

[m.reza]

Hi dear Lucy
I have your problem in Prandtl-udf about the function "rng_alpha"
I have read these header files in the "src" directory of my Fluent installation for rng_alpha ,but I don't underestand anything special for "rng_alpha".
Can you help me about written rng_alpha in the udf?
Thank you very much for help!

[m.reza]

Hi dear Lucy
I have your problem in Prandtl-udf for the function "rng_alpha"
I have read these header files in the "src" directory of my Fluent installation for rng_alpha ,but I don't underestand anything special for "rng_alpha".
Can you help me about written rng_alpha in the udf?
Thank you very much for help!