Learning Forum

[kiran.purushothamakeshavan]

I get this error when I use run simulation with this UDF:

#include "udf.h"

#include "dpm.h"

#include

#define Rho_air 1.225

#define mu 0.5

#define PI 3.14

#define VISC 1.7894e-05 // dynamic viscosity of air

#define Rho_p 1550

FILE *fp1;

DEFINE_DPM_DRAG(particle_drag_force, Re, p)

{    

    real b1, b2, b3, b4, Cd, drag_force, A, radius, df;

    real shf = 1;

    real nf, ff;

    Thread* tcell = P_CELL_THREAD(p);

    cell_t c = P_CELL(p);

    real relVel[ND_3], dvtdn, fluidVel[ND_3];

    // Fluid velocity

    NV_D(fluidVel, =, C_U(c, tcell), C_V(c, tcell), C_W(c, tcell));  // Assign fluid velocity components to vector

    // Relative velocity

    NV_VV(relVel, =, fluidVel, -, P_VEL(p));                         // Calculate relative velocity of flow on particle by subtracting absolute particle velocity from fluid velocity

    dvtdn = NV_MAG(relVel);                                          // Calculate relative velocity magnitude

    radius = P_DIAM(p) / 2.0;

    A = PI * radius * radius;

    b1 = exp(2.3288 - 6.4581 * shf + 2.4456 * pow(shf, 2));

    b2 = 0.0964 + 0.5565 * shf;

    b3 = exp(4.905 - 13.8944 * shf + 18.4222 * pow(shf, 2) - 10.2599 * pow(shf, 3));

    b4 = exp(1.4681 + 12.2584 * shf - 20.7322 * pow(shf, 2) + 15.8855 * pow(shf, 3));

    Cd = (24 * (1 + b1 * pow(Re, b2)) / Re) + (b3 * Re / (b4 + Re));

    // Store drag force and other quantities in UDMs

    df = (1 / 2) * Rho_p * A * Cd * (dvtdn * dvtdn);

    // Store quantities in UDMs

    C_UDMI(c, tcell, 0) = df;           // Store drag force

    C_UDMI(c, tcell, 1) = dvtdn;        // Store relative velocity

    nf = C_P(c, tcell) * A;       // Calculate some quantity 'nf'

    C_UDMI(c, tcell, 2) = nf;           // Store 'nf'

    ff = mu * nf;                 // Calculate some quantity 'ff'

    C_UDMI(c, tcell, 3) = ff;           // Store 'ff'

    C_UDMI(c, tcell, 4) = C_P(c, tcell); // Store cell pressure

    P_USER_REAL(p, 0) = df;

    P_USER_REAL(p, 1) = dvtdn;

    P_USER_REAL(p, 2) = nf;

    P_USER_REAL(p, 3) = ff;

    P_USER_REAL(p, 4) = C_P(c, tcell);

    fp1=fopen ("Impact1.txt" , "a") ;

    fprintf( fp1 , "%f %f %f %f %f\n", P_USER_REAL(p, 0), P_USER_REAL(p, 1), P_USER_REAL(p, 2), P_USER_REAL(p, 3), P_USER_REAL(p, 4));

    fclose(fp1);

    // Calculate drag force

    drag_force = (18 * Cd * Re) / 24;                // is this taking the reynolds number of the particle or the flow?

    return drag_force;

}

 

Can you please tell me what this error is??

 

Thanks,
Kiran

[Rob]

Were there any compilation warnings? I'm not going to debug code.