[aximefu]

Now I want to simulate the phenomena of phase change and fluid flow in heat pipe with Fluent. When I initialize the solution, an eror appeared as follow:
Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
1. Note exact events leading to error.
2. Save case/data under new name.
3. Exit program and restart to continue.
4. Report error to your distributor.
Error Object: ()

In this simulation, I want to use UDF of evaporation and condensation as follow, Would anyone help me checking it?

#include "udf.h"
#include "sg_mphase.h"
#define T_SAT 298
#define LAT_HT 2442
DEFINE_SOURCE(liq_src, cell, pri_th, dS, eqn)
{
Thread *mix_th, *sec_th;
real m_dot_l;
mix_th = THREAD_SUPER_THREAD(pri_th);
sec_th = THREAD_SUB_THREAD(mix_th, 1);
if(C_T(cell, mix_th)>=T_SAT)
{
m_dot_l = -0.1*C_VOF(cell, pri_th)*C_R(cell, pri_th)*
fabs(C_T(cell, mix_th) - T_SAT)/T_SAT;
dS[eqn] = -0.1*C_R(cell, pri_th)*fabs(C_T(cell, mix_th) - T_SAT)/T_SAT;

}
else {
m_dot_l = 0.1*C_VOF(cell, sec_th)*C_R(cell, sec_th)*
fabs(T_SAT-C_T(cell,mix_th))/T_SAT;
dS[eqn] = 0.;
}
return m_dot_l;
}

DEFINE_SOURCE(vap_src, cell, sec_th, dS, eqn)
{
Thread * mix_th, *pri_th;
real m_dot_v;
mix_th = THREAD_SUPER_THREAD(sec_th);
pri_th = THREAD_SUB_THREAD(mix_th, 0);
if(C_T(cell, mix_th)>=T_SAT)
{
m_dot_v = 0.1*C_VOF(cell, pri_th)*C_R(cell, pri_th)*
fabs(C_T(cell, mix_th) - T_SAT)/T_SAT;
dS[eqn] = 0.;
}
else {
m_dot_v = -0.1*C_VOF(cell, sec_th)*C_R(cell, sec_th)*
fabs(T_SAT-C_T(cell,mix_th))/T_SAT;

dS[eqn] = -0.1*C_R(cell, sec_th)* fabs(C_T(cell, mix_th) - T_SAT)/T_SAT;

}
return m_dot_v;
}

DEFINE_SOURCE(enrg_src, cell, mix_th, dS, eqn)
{
Thread *pri_th, *sec_th;
real m_dot;
pri_th = THREAD_SUB_THREAD(mix_th, 0);
sec_th = THREAD_SUB_THREAD(mix_th, 1);
if(C_T(cell, mix_th)>=T_SAT)
{
m_dot = -0.1*C_VOF(cell, pri_th)*C_R(cell, pri_th)*
fabs(C_T(cell, mix_th) - T_SAT)/T_SAT;
dS[eqn] = -0.1*C_VOF(cell, pri_th)*C_R(cell, pri_th)/T_SAT;
}
else {
m_dot = 0.1*C_VOF(cell, sec_th)*C_R(cell, sec_th)*
fabs(T_SAT-C_T(cell,mix_th))/T_SAT;
dS[eqn] = 0.1*C_VOF(cell, sec_th)*C_R(cell, sec_th)/T_SAT;}
return LAT_HT*m_dot;
}