hello guys,

iam writing a udf to alter the volume reaction rate and would like to use the partial pressures of species in it. can anybody please tell me if there is a way i ca access species partial pressure/mole fraction directly from the solver to use in my rate calculations. Thanks in advance guys, i would really appreciate this help. Thank you, siva

Fluent solves for the mass fraction of the species. Convert this to mole fraction, which is directly proportional to the partial pressure.

You can try to get the mol wt of the i_th species in your materials name list (total number of species = solver_par.nSpecies) by using solver_par.molWeight[i] in a compiled UDF...or maybe there is a more direct way since mole fraction is available from the field functions list. Check with Fluent Inc.

thanks lanre. can i use the molweight macro only in a compiled udf, can i use it in a interpreted udf, coz im unable to setup my compiled udf library-im faced with a problem-while i follow the procedure given in manuals, i keep getting the error message: language optional software package not installed-do u think ur familiar with this problem, if so can u please help me. thanks a lot in advance. siva