April 5, 2024 at 8:41 am
vikram chahal
Subscriber

could you please provide the UDF code. i have write this one 

#include "udf.h"

DEFINE_SOURCE(moment_source, c, t, dS, eqn)
{
    real time = CURRENT_TIME; // Get the current simulation time
    real moment = 0.0; // Initialize moment to zero
    real CG[ND_ND]; // Center of gravity coordinates
    real cellCG[ND_ND]; // Cell center coordinates

    C_CENTROID(CG, c, t); // Get CG of the domain
    C_CENTROID(cellCG, c, t); // Get cell center coordinates

    real distance_from_CG = cellCG[2] - CG[2]; // Distance along z-axis

    /* Check if time is within the specified duration */
    if (time <= 2.0)
    {
        /* Apply moment only to cells at CG */
        if (distance_from_CG = 0.0)
        {
            moment = 5000.0; // Apply 5000 Nm moment
    }

    dS[eqn] = 0.0; // Reset the source term
    return moment; // Return the moment as the source term
}

and hooked as the souce term of fluid domain under cell conditions.