[mariam.sara]

Sorry here is the correct expression.

mariam

[AlexanderZ]

Ts and TL should be defined by you

#include "udf.h"

#define cps 1800.0
#define cpl 2400.0
#define lat 160000.0

DEFINE_SPECIFIC_HEAT(cell_cp, T, Tref, h, yi)
{
real cpm,dt,coef;
real Tl, Ts; // to be defined
Tref = 308;
if T<Ts
	coef = 0;
else if T< Tl
	coef  = (T-Ts)/(Tl-Ts);
else
	coef = 1;
dt=exp(-T*(T-Tref)*(T-Tref)/4.0)/sqrt(4.0*3.14);
cpm =cps+(cpl-cps)*coef+lat*dt;
*h = cpm*(T-Tref);
return cpm;
}

best regards