Custom DPM laws using UDF
 

Hi all
I am injecting particles in plasma spray jet and need to find the solid heating of the particle with respect to time.
The formula used is
When the particle is less than melting point then DTp= DT *(6*dh/(PI*dp^3*cpp*rhop)

I wrote this in custom DPM law using UDF given below.
Can anyone help me to correct this UDF. And am very new to fluent and UDF it would be a grateful anybody help me at the earliest... Already am running out of time.

#include "udf.h"
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "surf.h"
#include "random.h"
#include "prop.h"
#include <math.h>
#include "mem.h"
#include "metric.h"
#include "dpm.h"
#include "dpm_types.h"
#include "dpm_laws.h"

#define CVIS 0.0037866 /*viscosity at 1310K */
#define PI 3.14


DEFINE_DPM_LAW(user_law,p,ci)
{
Material*m = P_MATERIAL(p);
Thread*t0=P_CELL_THREAD(p);
cell_t c = P_CELL(p);

real Tg,thermcnd,Tp,mp,Dp,Ap,Pr,cpp,cpg,visg,Nu,h,times tep,dh,dT,Re,aux5,rel_vel,TM=1358.0;
float x=0,dx;

Tg = C_T(c,t0); /*gas temperature */
visg = C_MU_T(c,t0); /*turbulent viscosity of gas*/
thermcnd = C_K_L(c,t0); /*thermal conductivity of gas*/
cpg = C_CP(c,t0); /*specific heat of gas*/
Tp = P_T(p); /* particle temperature */
mp = P_MASS(p); /* particle mass */
Dp = DPM_DIAM_FROM_VOL(mp / P_RHO(p)); /* particle diameter */
Ap = DPM_AREA(Dp); /* particle surface */
Pr = (cpg * visg)/thermcnd; /* Prandtl number */


cpp = DPM_SPECIFIC_HEAT(p,P_T(p)); /* particle specific heat*/


rel_vel= sqrt(pow((P_VEL(p)[0]-C_U(c,t0)),2.0)+pow((P_VEL(p)[1]-C_V(c,t0)),2.0));
aux5=((rel_vel* Dp * P_RHO(p))/CVIS); /* reynolds number */

Nu = (2.0 + 0.66 * sqrt(aux5) * pow(Pr, 1.0/3.0))); /* Nusselt number */
h = (Nu * thermcnd) / Dp; /* Heat transfer coefficient*/
timestep = P_DT(p);

dh = h * (Tg - Tp) * Ap; /* heat source term*/


dT =timestep*(6*dh/(PI*pow(Dp,3.0)*cpp*P_RHO(p)));
P_T(p)= P_T(p)+dT;
}

Kindly someone reply me....

What is the error you are getting? Can you explain?