[dinhanh]

Dear Fluent-user,

I wrote the UDF file to visualize the cavitation source term. In that: if P(c,t)>Pv the condensation occurs, else, the evaporation occurs.

However, the visualization from my UDF, the condensation occurs even P(c,t)<Pv. I do not find the exist problem in the code.

The code is following:

#include "udf.h"
#include "math.h"
#include "mem.h"
#include "sg_mem.h"

#define rho_V 0.0163
#define rho_L 998.4
#define pv 2198.0
DEFINE_ADJUST(Singhal_model,d)
{
d=Get_Domain(1);
Thread *t;
cell_t c;
double gamma,pv_t,eva,con,n,Rb;
thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
eva=0.0;
con=0.0;
pv_t=0.0;
gamma =(C_R(c,t)-rho_L)/(rho_V-rho_L);
pv_t=pv+0.5*0.39*C_R(c,t)*C_K(c,t);
n=pow(10.0,13.0);
if(gamma<0.0001)
{
gamma=0.0001;
}
Rb=pow(gamma/(1.0-gamma)*3.0/4.0/3.14/n,(1.0/3.0));
if(pv_t!=C_P(c,t))
{
eva=MAX(0.0,(pv_t-C_P(c,t)))/fabs(pv_t-C_P(c,t))*sqrt(C_K(c,t))/gamma/sqrt(C_R(c,t))*Rb;
con=MAX(0.0,(-pv_t+C_P(c,t)))/fabs(pv_t-C_P(c,t))*sqrt(C_K(c,t))/(1.0-gamma)*Rb;
}
C_UDMI(c,t,0)=eva;
C_UDMI(c,t,1)=con;
}
end_c_loop(c,t)
}
}


Someone please help me!!!
It is very importance for my work. Thank you very much.

[dinhanh]

Anyone please help!!