[Jerol]

Hello Everyone,

I am relatively new with UDF concept in fluent. So, kindly help me.

I want to impose a variable temperature along the wall (x-axis) which varies linearly (493 K to 473 K) and I want the temperature to reduce to 298 k after an hour. So, I went and wrote this code, but I am not sure if this is the correct way. Kindly, correct me if this is wrong.

Thank you \

Code:

#include "udf.h"

DEFINE_PROFILE(temp, thread, position)
{
face_t f;
real x;
real t = CURRENT_TIME;

begin_f_loop(f, thread)
{
x = F_T(f,thread);
if (t<3600)
F_PROFILE(f, thread, position) = 493 - 66.667 * x;

else

F_PROFILE(f, thread, position) = 298;
}
end_f_loop(f, thread)
}

[MayTheFlowBeWithYou]

It's almost correct:

#include "udf.h"

DEFINE_PROFILE(temp, thread, position)
{
face_t f;
real x;
real t = CURRENT_TIME;

begin_f_loop(f, thread)
{
x = F_T(f,thread);

if (t<3600){
F_PROFILE(f, thread, position) = 493 - 66.667 * x;
}
else
{
F_PROFILE(f, thread, position) = 298;
}
}
end_f_loop(f, thread)
}

[Oula]

Dear Jerol and MayTheFlowBeWithYou

Thank you for sharing these codes, in my case I need to inject a certain amount of gas flow rate through an inlet pipe, the injection of the gas is periodic during the simulation i.e. same amount of gas flow rate to be injected every one hour of the physical flow time. Do you know how can I code a UDF for this case

Any help is appreciated.

[gouravjee]

Originally Posted by MayTheFlowBeWithYou

It's almost correct:

#include "udf.h"

DEFINE_PROFILE(temp, thread, position)
{
face_t f;
real x;
real t = CURRENT_TIME;

begin_f_loop(f, thread)
{
x = F_T(f,thread);

if (t<3600){
F_PROFILE(f, thread, position) = 493 - 66.667 * x;
}
else
{
F_PROFILE(f, thread, position) = 298;
}
}
end_f_loop(f, thread)
}

Hii All,
I have been working on a heat exchanger problem in which the molten metal kept stationary in outer shell of a concentric tube and a fluid is flowing in the inner tube.
I am using UDS scalars to define temperature and velocity but results do not show any variation in temperature profile of fluid part(even if flow is there) and remains same as the stationary fluid
kindly provide me some hint regarding this problem

Thanks in Advance