Please help me check if there are any issues with the UDF.

[24212040751]

The paper I referred to is:

Xu W, Dong CJ, Li DS. Numerical simulation on influences of wind speed to leaking diffusion of liquid ammonia. Advanced Materials Research. 2015 Jan 27;1073:383-7.

 

#include "udf.h"

#define T_evap -33.0   // Evaporation temperature in Celsius

DEFINE_PROPERTY(gasification_model, c, t)

{

    real T_d = C_T(c, t);  // Temperature of the droplet

    real T_env = C_T(c, t); // Temperature of the surrounding environment

    real m_d = C_MASS(c, t); // Mass of the droplet

    real c_d = 2.0;  // Specific heat of the droplet (example value)

    real A_d = 0.1;  // Surface area of the droplet (example value)

    real h = 1000.0; // Heat transfer coefficient (example value)

    real h_latent = 2260.0; // Latent heat of vaporization for ammonia (J/g)

    // Check if the droplet is in the liquid phase (T_d < T_evap)

    if (T_d < T_evap) {

        // Liquid phase: Apply heat transfer equation

        return h * A_d * (T_env - T_d) / (m_d * c_d);

    }

    else {

        // Gas phase: Apply phase change equation with latent heat

        return h * A_d * (T_d - T_env) / (m_d * c_d) + h_latent;

    }

}

DEFINE_DPM_FORCE(droplet_force, f, t, c, dt)

{

    real u = C_U(c,t); // Velocity of the droplet

    real v = C_V(c,t); // Velocity of the droplet

    real w = C_W(c,t); // Velocity of the droplet

    real gravity = 9.81; // Acceleration due to gravity

    real drag_force = calculate_drag_force(u, v, w); // Call function for drag force calculation

    // Additional forces like Brownian, added mass can be defined here

    return drag_force + gravity;

}

[Rob]

See comments  https://innovationspace.ansys.com/forum/forums/topic/compile-the-udf-code-and-apply-it-to-the-dpm/  

What is the DPM_FORCE for as gravity & flow are already included by default.