Reply To: source term modification of energy equation in non-equilibrium thermal model

[yf70512]

Here is my UDF：

#include "udf.h"

#define HFS_CONSTANT 1000   
#define AFS_CONSTANT 0.1    

// Fluid Source Term
DEFINE_SOURCE(Fluid_source, c, t, dS, eqn)
{
    real Tf, Ts;
    real hfs, Afs;
    real source;

    // Obtain the fluid temperature (Tf) and solid temperature (Ts)
    Tf = C_STORAGE_R(c, t, SV_T_F);   // Access fluid temperature
    Ts = C_STORAGE_R(c, t, SV_T_S);   // Access solid temperature
    
    // Calculate or use constants for hfs (heat transfer coefficient) and Afs (interfacial area density)
    hfs = HFS_CONSTANT;  // Define or calculate hfs
    Afs = AFS_CONSTANT;  // Define or calculate Afs

    // Calculate the source term using modified expression hA(Tf^4 - Ts^4)
    source = hfs * Afs * (pow(Ts, 4) - pow(Tf, 4));

    // Define the derivative of the source term with respect to Tf
    dS[eqn] = -4 * hfs * Afs * pow(Tf, 3);

    return source;  // Return the calculated source term
}

// Solid Source Term
DEFINE_SOURCE(Solid_source, c, t, dS, eqn)
{
    real Tf, Ts;
    real hfs, Afs;
    real source;

    // Obtain the fluid temperature (Tf) and solid temperature (Ts)
    Ts = C_STORAGE_R(c, t, SV_T_S);   // Access solid temperature
    Tf = C_STORAGE_R(c, t, SV_T_F);   // Access fluid temperature

    // Calculate or use constants for hfs (heat transfer coefficient) and Afs (interfacial area density)
    hfs = HFS_CONSTANT;  // Define or calculate hfs
    Afs = AFS_CONSTANT;  // Define or calculate Afs

    // Calculate the source term using modified expression hA(Ts^4 - Tf^4)
    source = hfs * Afs * (pow(Ts, 4) - pow(Tf, 4));

    // Define the derivative of the source term with respect to Ts
    dS[eqn] = 4 * hfs * Afs * pow(Ts, 3);

    return source;  // Return the calculated source term
}

I am not sure if it is right to access the  solid temperature in the fluid zone and fluid temperature in the solid zone.