haw to get access to one species from mixure? I want to do an if-else statement over one species from mixture. It should be something like this: if thread = fluid thread and species = species 1 (there are two species in mixture) than..... etc. is it possible?? Can you tell me how to write this ? thank you for your time

so it is impossible?? .....it`s too bad. Even gurus don`t know???

Your question is so open-ended as to be impossible to answer. In order to formulate a response, information such as the construction of the data structures in your code and what type of mixture you are referring to (as well as the language you are using) should probably be provided.

You are right

We are using c+ language. Physical Model: container - filled 1/2 of volume with solution (bottom) and vapour (upper part). In Fluent data are: solver-unstady, multiphase-VOF (2phase - GEO Rec.), energy - enabled, species react.-enabled (w/o reactions, w/o diffusion), viscoscous - K-eps, Materials: solution (mixture) and vapour h2o. Phases: primary phase solution, secondary - vapour. I know it should be prim. vapour, sec. solution in VOF (my mistake). operating condiotions: enablet gravity and specifeed density. BC - heated wall 500K, its thicknes 0,001m, upper wall is outflow. Solution ; U-Relax. all between 0.3-0.7, discretiz. pressure body weighted , rest second order. Initialize: solution temperature 370 K, mass fraction of 1 in sol. = 0.55.

bellow is my udf code. is it ok. We want mass transfer only from h2o(l) to h2o(v) and from h2o(v) to h2o (l). h2o (l) is a part of solution

#include "udf.h"

DEFINE_MASS_TRANSFER(dm,cell,thread,od_faza,od_skl adnik, do_faza,do_skladnik) { int iciecz,igaz,iH2O,iLiBr; real masa,m_lg; real T_SAT = 373;

m_lg = 0.; iciecz=0; igaz=1; iH2O=1; iLiBr=0;

if(od_skladnik == iLiBr) goto koniec;

if(do_skladnik == iLiBr) goto koniec;

if(od_faza == iciecz)

{ Thread *gas=THREAD_SUB_THREAD(thread, do_faza); Thread *liq=THREAD_SUB_THREAD(thread, od_faza); if (C_T(cell, liq) >= T_SAT) { m_lg = 0.1*C_VOF(cell,liq)*C_R(cell,liq)* fabs(C_T(cell,liq)-T_SAT)/T_SAT; } 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; } } else { Thread *gas=THREAD_SUB_THREAD(thread, od_faza); Thread *liq=THREAD_SUB_THREAD(thread, do_faza); if (C_T(cell, liq) >= T_SAT) { m_lg = -0.1*C_VOF(cell,liq)*C_R(cell,liq)* fabs(C_T(cell,liq)-T_SAT)/T_SAT; } 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; } } koniec: { masa=m_lg; return (masa); } }

In this udf the problem is the water doesnt want to boil. If we had some other udf (I have it somewhere) water boils but with the rest of solution. that is my proble thank you