## Fluids

#### DPM MASS SOURCE

• zeeshe
Subscriber
I, Muhammad Zeeshan, is working on Water Spray System and its application in Urban Physics.   I have finalized the UDF (Attached) in light of FLUENT Guideline for dpm mass exchange source  as given in figure

Kindly go through it and highlight the necessary emendations if any.
Actually  I have been stuck at this point. Plz help me. Kindly send some reference DPM Source and scaler UDF. My udf as per The fluent manual referred UDF is not working.

Waiting for your  kind response

• zeeshe
Subscriber

#include "udf.h"

#include "dpm.h"

#define P_RHO(p) 998;

#define rhoa 1.125;

#define CP_AIR 100643;

#define MU_AIR .000017894;

#define pi 3.1416;

#define alpham .3; //*As defined during dpm setup*/

#define K_AIR .0242;

#define Mv=18.02;

#define Ma=28.57;

#define dmean=.000007;

#define P=101325; //P=local absolute pressure as defined in material property;

#define mp_dot=.021  ;//as defined in injection parameter

#define alpham=.3;

#define Tref=298.4;

#define Tbp=373;

DEFINE_DPM_SOURCE(dpm_source,c,t,S,strength,p) //function type incompatible with previous definition (function returning void instead of float)

{

real mp_dot0;

real mp0= P_INIT_MASS(p);

real mp = P_MASS(p);

/* get Cell and thread from particle structure*/

//cell_t c = P_CELL(p);

//real D = DPM_BINARY_DIFFUSIVITY(p,m,t); /* diffusion coefficient */

{

real P_DIAM(p) = pow(6.0 * P_MASS(p) / (P_RHO(p) * M_PI), 1./3.); //* real Dp = DPM_DIAM_FROM_VOL(mp / P_RHO(p)); /* particle diameter */

mp0 = (pi/6)*P_RHO(p)*pow(dmean, 3.0);

mp = (pi/6)*P_RHO(p)*pow(P_DIAM(p), 3.0);

Delmp = mp*alpham;

mp_dot0=mp0*strength;

S->mass = delmp*mp_dot0/mp0;

}

• DrAmine
Ansys Employee
there is an example in the customization manual.
• DrAmine
Ansys Employee
To change the mass without any interaction you should not change NY source.
• zeeshe
Subscriber

I am considering TWO WAY COUPLING between continuous and discrete phase for which the following are the exchange sources:

I just wanted to confirm whether these coupling sources have to be implemented via UDF or these first have to be calculated from ANSYS Simulation and then applied these sources values in next iteration/simulation.

BR

Zeeshan

• DrAmine
Ansys Employee
I meant mass and latent heat transfer with the continuous phase. Dpm source udf is meant for that.
• zeeshe
Subscriber

Ok I got it. That ok.

I am considering TWO WAY COUPLING between continuous and discrete phase using the exchange sources.

I just wanted to confirm whether these coupling sources have to be implemented via UDF?

or these first have to be calculated from ANSYS Simulation and then applied these sources values in next iteration/simulation?