How to control the boiling zone
 

I am modelling a gas-liquid two-phase model with a boiling process(VOF model for now),and I want to keep the boiling process in a fixed area.
I set the overheat temperature to 374K, and I hope to get a steady boiling height. I have tried to define the relationship between saturation pressure and boiling point in a table or UDF. But in this way, I still cannot control the boiling height precisely.
Then I am wondering if I can defining the relationship between property and position.

The original udf is shown below:

#include "udf.h"
DEFINE_PROPERTY(saturation_temp,c,t)
{
real sat_t;
real vapor_p;
real static_p;
real operating_p;
static_p=C_P(c,t);
operating_p = RP_Get_Float("operating-pressure");
vapor_p = static_p + operating_p;
sat_t = 1723.6425/(8.05573-log(vapor_p/133.322))-233.08+273.15;
return sat_t;
}

Then I want to define the property changing with height in order to control the bioing zone(represented by height Y), so I changed the UDF then it comes to a failure:

#include "udf.h"
DEFINE_PROPERTY(saturation_temp,c,t)
{
cell_t c;
Thread *t;
real xc[ND_ND];
real x;
real y;
real sat_t;
real vapor_p;
real static_p;
real operating_p;
thread_loop_c(t,d)
{
begin_c_loop_all(c,t)
{
x=xc[0];
y=yc[1];
if (y<0.6||y>0.8)
sat_t = 500
else
static_p=C_P(c,t);
operating_p = RP_Get_Float("operating-pressure");
vapor_p = static_p + operating_p;
sat_t = 1723.6425/(8.05573-log(vapor_p/133.322))-233.08+273.15;
return sat_t;
}
end_f_loop(c,t);
}
}


So, if it possible to define the property, saturation temp, changing with location？And if there's any other way to control the boiling height exactly?

i recommend you to compile your code always, so you would see where the problem is
xc is not defined in your code

part of code after esle should be in brackets