[Anurag_B]

Hello everyone, I am trying to write a code that modifies the DPM_HEAT_MASS and also DPM_LAW. I am modifying some user reals inside DPM_HEAT_MASS which is used to overwrite particle mass, density etc inside DPM_LAW. I am not sure how to include my DPM_HEAT_MASS in DPM_LAW. When i try to print, i find the messages inside DPM_HEAT_MASS is not getting printed. Please let me know if you have any pointers.

Some snippets from my code like this-

#include "udf.h"
#include "dpm_mem.h"

#define DPM_DT (1.e-7)
#define NUM_DP 5 // NUMBER OF LAYERS INSIDE DROPLET
#define PI 3.1415926
#define solid_mfrac 0.45
#define drop_moist_cont 1.22
#define rho_s 1100.0
#define rho_l 1000.0
#define Dsl_solid 2.94e-10

/* heat and mass transfer */
DEFINE_DPM_HEAT_MASS(multivap,tp,Cp,hgas,hvap,cvap _surf,Z,dydt,dzdt)
{

//USER DEFINED VARIABES
real r_droplet[NUM_DP];
real conc_droplet[NUM_DP];

int ns;
Material *sp;
real count;
...
Message("Diameter: %e\n", TP_DIAM(tp)); //to check it enters the multivap
...

/* update the user scalar variables */
DEFINE_DPM_SCALAR_UPDATE(concentration_particle,ce ll,thread,initialize,tp)
{
if (TP_TIME(tp) == tp->time_of_birth)
{
real Rp_0 = 0.5*TP_INIT_DIAM(tp);
real rho_d_0 = TP_INIT_RHO(tp);
real mp_0 = TP_INIT_MASS(tp);
...
TP_USER_REAL(tp,NUM_DP) = mp_0; /* initial particle mass*/
...
}


DEFINE_DPM_LAW(Slurry_model,tp,ci)
{

//VaporizatonLaw(tp); I am using my own vaporization code from heat_mass?

/* Computing initial properties considering solid content*/
TP_INIT_RHO(tp) = ((1+drop_moist_cont)*rho_s*rho_l)/(rho_l+(drop_moist_cont*rho_s));
TP_INIT_MASS(tp) = 4*PI*pow((0.5*TP_INIT_DIAM(tp)),3.)*TP_INIT_RHO(tp )/3;

/* compute new particle diameter, density and mass */
TP_MASS(tp) -= TP_USER_REAL(tp,NUM_DP+6)*DPM_DT;
TP_DIAM(tp) += 2*TP_USER_REAL(tp,NUM_DP+5)*DPM_DT;
TP_RHO(tp) = ((1+TP_USER_REAL(tp,NUM_DP+7))*rho_s*rho_l)/(rho_l+(TP_USER_REAL(tp,NUM_DP+7)*rho_s));

Message("Mass: %e\n Rho: %e\n", TP_MASS(tp), TP_RHO(tp));
}

[rewol]

Hello,

I am not sure that DEFINE_DPM_HEAT_MASS and DEFINE_DPM_LAW are meant to be used together. As far as i know, DEFINE_DPM_HEAT_MASS is for multicomponent liquid phase. In the corresponding UDF example code, you can see that vaporization and boiling are coded together.

If you already know the equations that will govern your vaporization and boiling and know when to switch between them, you do not need DEFINE_DPM_LAW macro. DEFINE_DPM_HEAT_MASS macro contains pointers that you have to adress to HANDLE source terms.

Hope this helps.

Refik