CONSTRAINED-EQUILIBRIUM CALCULATIONS FOR CHEMICAL-SYSTEMS SUBJECT TO GENERALIZED LINEAR CONSTRAINTS USING THE NASA AND STANJAN EQUILIBRIUM PROGRAMS

Citation
Ps. Bishnu et al., CONSTRAINED-EQUILIBRIUM CALCULATIONS FOR CHEMICAL-SYSTEMS SUBJECT TO GENERALIZED LINEAR CONSTRAINTS USING THE NASA AND STANJAN EQUILIBRIUM PROGRAMS, COMBUSTION THEORY AND MODELLING, 1(3), 1997, pp. 295-312
Citations number
11
Categorie Soggetti
Mathematics,Mathematics,Thermodynamics,"Energy & Fuels","Engineering, Chemical
ISSN journal
13647830
Volume
1
Issue
3
Year of publication
1997
Pages
295 - 312
Database
ISI
SICI code
1364-7830(1997)1:3<295:CCFCST>2.0.ZU;2-3
Abstract
Fast efficient numerical programs for determining the equilibrium comp osition of large chemical systems subject to generalized linear constr aints are needed for chemical kinetic calculations involving both the conventional local thermodynamic equilibrium (LTE) and the more genera l rate-controlled constrained-equilibrium RCCE assumptions. For this p urpose two callable subroutines based on the well known NASA and STANJ AN equilibrium codes have been developed by a simple modification of t heir input files. To evaluate the performance of these subroutines, te st calculations have been made for the hydrogen-oxygen (H-O) and carbo n- hydrogen-oxygen-nitrogen (C-H-O-N) systems with various combination s of constraints on the elements, the total moles and the free valence (number of unpaired electrons) in the system. The allowed domain of t he constraints was determined and both interior and boundary points we re investigated for several temperature and pressure conditions. The r esults showed that STANJAN was superior to NASA both in convergence an d speed under all conditions investigated.