Reply To: Momentum source UDF in Eulerian Multiphase Flow (Fluent)

[Asif Shahriar Nafi]

If my understanding is correct:
for water (phase 1) - air (phase 2) flow (Eulerian Multiphase): 

A UDF for Phase 1 x-momentum source can be written as:

DEFINE_SOURCE(xmom_source,cell, mixture_thread, dS, eqn)

{    

    int phase1_domain_index = 0;           /* primary (water) phase-1 index is 0     */
    int phase2_domain_index = 1;           /* secondary (air) phase-2 index is 1    */

    Thread *mixture_thread;               /* mixture-level thread pointer */

    Thread *water = THREAD_SUB_THREAD(mixture_thread,phase1_domain_index); 

    Thread *air = THREAD_SUB_THREAD(mixture_thread,phase2_domain_index);

       water_U_Velocity = C_U(cell, water);

       water_VOF = C_VOF(cell, water);

       air_U_Velocity = C_U(cell, air);

       air_VOF = C_VOF(cell, air);

 

       source = water_VOF*water_U_Velocity*air_VOF*air_U_Velocity;

       return source ;

}

Please let me know if my assumption is correct ?
Thanks in Advance