[esantana]

Hi!

im trying to make a transient planar model in which there is a time dependent heat flux (1.67e+17 W/m^2) during a period of time (60ns). The geometry is a rectangle and only one side has this condition. I need to study the phase change that happens to the fluid inside the domain and the effects of such. To define the heat flux I'm trying to use a user defined function but I'm not skilled at C therefore I've been reading threads for a while and have come up with what I tough was the function I needed. Fluent interprets it without errors but I a message during simulation that says:


chip-exec: heat_flux: argument 1: incorrect type (38): int expectedchip-exec: heat_flux: argument 2: incorrect type (5): pointer expectedchip-exec: heat_flux: argument 3: incorrect type (0)


(every iteration with the same and different numbers for argument and type())



and when the simulation ends if I see the results they are as if there was no heat flux at all. (The geometry is really small 5e-11m^2 so there's supposed to at least be a rise in temperature but there isn't). The code I'm using is the following:


/************************************************** *********************
heatflux.c
UDF for specyjfuing a transient heat flux boundary condition
************************************************** *********************/

#include "udf.h"
DEFINE_PROFILE(heat_flux, thread, i)

{
face_t f;
Thread *f_thread;
real t=CURRENT_TIME;
if (t<=60e-9)
{real a=1.67e+17;}
else
{real a=0;}

}



Any help would be very appreciated.

[obscureed]

Hi Enrique,

The short answer: follow the examples in the manual.

If your DEFINE_PROFILE does not contain begin_f_loop ... end_f_loop (or, much less typically, the equivalent cell loop), then you are probably doing it wrong. The manual is very clear on this.

It is better (and sometimes essential) to define all your variables at the start -- the freedom to write "real a = 0.0;" in the middle of a function is not standard C. To be clear: write "real a;" near the start, and just "a = 0.0;" later.

I don't understand the error message. If you've checked the syntax of DEFINE_PROFILE for the version you're using, then it's time to be paranoid: delete the blank line between DEFINE_PROFILE and {.

Good luck!
Ed

[esantana]

Hi!


I've changed the code, now it looks like this:


/************************************************** *********************
heatflux.c
UDF for specyjfuing a transient heat flux boundary condition
************************************************** *********************/

#include "udf.h"
DEFINE_PROFILE(MP_heat_flux, thread, i);
{
real a;
real b;
b = CURRENT_TIME;
face_t f;
begin_f_loop(f, t)
{
if (b <= 60e-9)
{a=1.67e+17;}
else
{a = 0;}
F_PROFILE(f,thread,i) = a;
}
end_f_loop(f,t)
}


Now I'm getting a parse error in line 8. I know this must be a sintax error but I don't find where is it. I've tried changing the first curly braquet position to after the line that states: b = CURRENT_TIME; and the parse error moves to line 10. the same occurs if I move the braquet to after the line : face_t f;. But this time the error stays on line 10. Sorry to keep asking for help and thanks to anyone that helps.

[AlexanderZ]

remove ;

DEFINE_PROFILE(MP_heat_flux, thread, i);

should be

DEFINE_PROFILE(MP_heat_flux, thread, i)

best regards