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canev.civelek October 5, 2012 13:15

UDF for VOF model
Hi there,

Ive run a VOF spray simulation in FLUENT and now i wish to add a UDF to incorporate mass transfer (Evaporation) into the simulation.

I am aware there is a code given in the UDF user's guide, however im not sure exactually how it works. see below:

#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);
Thread *liq = THREAD_SUB_THREAD(thread, to_index);
m_lg = 0.;
if (C_T(cell, liq) >= T_SAT)
m_lg = -0.1*C_VOF(cell,liq)*C_R(cell,liq)*
if ((m_lg == 0. ) && (C_T(cell, gas) <= T_SAT))
m_lg = 0.1*C_VOF(cell,gas)*C_R(cell,gas)*
return (m_lg);

I have found a model by Hardt and Wondra which has been implemented in fluent before. I wish to add a mass source term and an evaporation source term as they did. These equations are published in their paper however im not sure how to implement this into fluent.

If anyone has any information, or could reccomend any sources which may be helpful i would really appreciate it.

Thanks :):)

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