{"id":362939,"date":"2024-04-18T12:37:56","date_gmt":"2024-04-18T12:37:56","guid":{"rendered":"\/forum\/forums\/topic\/udf-for-mass-transfer-pars-error\/"},"modified":"2024-04-18T12:47:33","modified_gmt":"2024-04-18T12:47:33","slug":"udf-for-mass-transfer-pars-error","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/udf-for-mass-transfer-pars-error\/","title":{"rendered":"UDF for mass transfer parse error"},"content":{"rendered":"

Hallo,
 I’m trying to write a udf to model the mass transfer equation indicated in the image below for condensation model 
the porblem is when i press interpret in fluent it gives me an error 
“line 13 parse error
line 14: parse error
line.15: parse error.
line 18: liq: undeclared variable”<\/p>\n

here is my UDF code <\/p>\n

\n
\/* UDF to define a simple mass transfer based on Saturation<\/div>\n
   Temperature. The “from” phase is the gas and the “to” phase is the<\/div>\n
   liquid phase  *\/<\/div>\n

<\/p>\n

#include “udf.h”<\/div>\n
DEFINE_MASS_TRANSFER(Th_conds, cell, thread, from_index,from_species_index, to_index, to_species_index)<\/div>\n
{<\/div>\n
   real m_lg;<\/div>\n
   real time_step;<\/div>\n
   time_step=5e-5;<\/div>\n
   real T_SAT = 309.15;<\/div>\n
   Thread *gas = THREAD_SUB_THREAD(thread, from_index);<\/div>\n
   Thread *liq = THREAD_SUB_THREAD(thread, to_index);<\/div>\n

<\/p>\n

   m_lg = 0;<\/div>\n
   if (C_T(cell, liq) >= T_SAT)<\/div>\n
     {<\/div>\n
       m_lg = – (C_R(cell,liq)*C_CP(cell,liq)*(C_T(cell,liq)-T_SAT))\/(time_step*C_H(cell,liq));    <\/div>\n
     }          <\/div>\n
   if ((m_lg == 0 ) && (C_T(cell, gas) <= T_SAT))<\/div>\n
     {<\/div>\n
       m_lg =  (C_R(cell,gas)*C_CP(cell,gas)*(C_T(cell,liq)-T_SAT))\/(time_step*C_H(cell,gas));  <\/div>\n
     }<\/div>\n

<\/p>\n

   return (m_lg);<\/div>\n
}<\/div>\n<\/div>\n

here is the mass transfer equation \"\"<\/a><\/p>\n","protected":false},"template":"","class_list":["post-362939","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t