[Anshs]

I am modeling a species mass transfer model, in which I want to transfer a species from one phase to another phase. I am trying to express this process with the last term of the equation given below. [ m_dot(p_j,q_i) = mass transfer of 'species j from p phase' to 'species i of q phase' ]

Screenshot 2020-05-23 at 10.31.53 AM.jpg

Can anyone please help me with a very basic example of which UDF macro to use and how may I assign the phases and the species?

[Anshs]

Any help on this post?

Thanks

[Anshs]

Originally Posted by Anshs

I am modeling a species mass transfer model, in which I want to transfer a species from one phase to another phase. I am trying to express this process with the last term of the equation given below. [ m_dot(p_j,q_i) = mass transfer of 'species j from p phase' to 'species i of q phase' ]

Attachment 77892

Can anyone please help me with a very basic example of which UDF macro to use and how may I assign the phases and the species?

I have tried to use the example given in the fluent tutorial.

#include "udf.h"

 

DEFINE_MASS_TRANSFER(liq_gas_source, cell, thread, from_index,

from_species_index, to_index, to_species_index)

{

   real m_lg;

   real T_SAT = 373.15;

   Thread *gas = THREAD_SUB_THREAD(thread, from_index);      // gas phase

   Thread *liq = THREAD_SUB_THREAD(thread, to_index);          // liquid phase

 

   m_lg = 0.;           // initialisation 


   if ((m_lg == 0. ) && (C_T(cell, gas) <= T_SAT))

     {

       m_lg = 0.1*C_VOF(cell,gas)*C_R(cell,gas)*

         fabs(T_SAT-C_T(cell,gas))/T_SAT;

          from_species_index = 0. (let's say the first species)
          to_species_index = 2. (let's say the third species)

        m_lg = 0.1* C_VOF(cell,gas) * C_R(cell,gas) * C_YI(c , gas , 0)  ;

//here C_YI(c, gas, 0 ), denotes species mass fraction of 1st species in the mixture denoted by phase 'gas'.

      }

   return (m_lg);

Is the above UDF correct?

But how will the UDF know whether to transfer the species to 'to_species_index = 2'?