Chemkin

R. J. Kee, J. A. Miller, and T. H. Jefferson, "CHEMKIN A General-Purpose, Problem-Independent, Transportable, FORTRAN Chemical Kinetics Code Package," DOE, Sandia Laboratory SAND80-8003, NTlS, Springfield, Va., Mar. 1980. 

The task of the problem-independent chemistry software is to make evaluating the terms in Equations (6-10) as straightforward as possible. In this case subroutine calls to the Chemkin software are made to return values of p, Cp, and the and hk vectors. Also, subroutine calls are made to a Transport package to return the ordinary multicomponent diffusion matrices Dkj, the mixture viscosities p, the thermal conductivities A, and the thermal diffusion coefficients D. Once this is done, finite difference representations of the equations are evaluated, and the residuals returned to the boundary value solver. 

Due to its modularity, the software comes in many parts (shown in Fig. 9). The Chemkin package is composed of four important pieces the Interpreter, the Thermodynamic Data Base, the Linking File, and the Gas-Phase Subroutine Library. The Interpreter is a program that first reads the user s symbolic description of the reaction mechanism. It then extracts thermodynamic information for the species involved from the Thermodynamic Data Base. The user may add to or modify the information in the data base by input to the Interpreter. In addition to printed output, the Interpreter writes a Linking File, which contains all the pertinent information on the elements, species, and reactions in the mechanism. 

Figure 9. Schematic representation of the relationship of the Chemkin and Transport software packages with an application code.

The Chemkin package deals with problems that can be stated in terms of equation of state, thermodynamic properties, and chemical kinetics, but it does not consider the effects of fluid transport. Once fluid transport is introduced it is usually necessary to model diffusive fluxes of mass, momentum, and energy, which requires knowledge of transport coefficients such as viscosity, thermal conductivity, species diffusion coefficients, and thermal diffusion coefficients. Therefore, in a software package analogous to Chemkin, we provide the capabilities for evaluating these coefficients. ... 

The rate constants (/c[and k]) and the stoichiometric coefficients (t and 1/ ) are all assumed to be known. Likewise, the reaction rate functions Rt for each reaction step, the equation of state for the density p, the specific enthalpies for the chemical species Hk, as well as the expression for the specific heat of the fluid cp must be provided. In most commercial CFD codes, user interfaces are available to simplify the input of these data. For example, for a combusting system with gas-phase chemistry, chemical databases such as Chemkin-II greatly simplify the process of supplying the detailed chemistry to a CFD code. 

Chemical databases for gas-phase chemistry such as Chemkin-II utilize this format for the chemical source term. 

The program, called Stanjan [8] (see Appendix I), is readily handled even on the most modest computers. Like the Gordon-McBride program, both approaches use the JANAF thermochemical database [1], The suite of CHEMKIN programs (see Appendix H) also provides an equilibrium code based on Stanjan [8],... 

The coefficients through a7 are generally provided for both high-and low-temperature ranges. Thermodynamic data in CHEMKIN format for liquid decane is given below. 

In the data above, the first line provides the chemical name, a comment, the elemental composition, the phase, and the temperature range over which the data are reported. In lines 2 through 4, the high-temperature coefficients ah..., a7 are presented first followed by the low temperature coefficients. For more information, refer to Kee et al. (Kee, R. J., Rupley, F. M and Miller, J. A., The Chemkin Thermodynamic Database, Sandia Report, SAND87-8215B, reprinted March 1991). 

Kee, R. J., Rupley, F. M., and Miller, J. A., CHEMKIN-II A FORTRAN Chemical Kinetics Package for the Analysis of Gas-Phase Chemical Kinetics, Sandia National Laboratories, Livermore, CA, Sandia Report SAWD89-8009, 1989. 

Kee, R. J. Miller, J. A. and Jefferson, T. H. Chemkin A General-Purpose, Problem-Independent Transportable, Fortran Chemical Kinetics Code Package , Sandia National Laboratories Report S AND80-8003, 1980. 

Burcat [ Thermochemical Data for Combustion Calculations, in Combustion Chemistry. (W. C. Gardiner, Jr., ed.), Chapter 8. John Wiley Sons, New York, 1984] discusses in detail the various sources of thermochemical data and their adaptation for computer usage. Examples of thermochemical data tit to polynomials for use in computer calculations are reported by McBride, B. J Gordon, S., and Reno, M. A., Coefficients for Calculating Thermodynamic and Transport Properties of Individual Species, NASA, NASA Langley, VA, NASA Technical Memorandum 4513, 1993, and by Kee, R. J., Rupley, F. M and Miller, J. A., The Chemkin Thermodynamic Data Base, Sandia National Laboratories, Livermore, CA, Sandia Technical Report SAND87-8215B, 1987. 

CHEMKIN is now maintained and distributed by Reaction Design, Inc., which is a software company licensed by Sandia National Laboratories. CHEMKIN 4.1 is the latest commercial version of the CHEMKIN software suite from Reaction Design. The software suite has all the application modules of CHEMKIN II and III (such as SURFACE CHEMKIN, EQUIL, SENKIN, PSR, and PREMIX), and has been extended to include many more. Refer to the website http //www.reactiondesign.com/lobby/open/index.html for more information. 

SURFTHERM Coltrin, M. E. and Moffat, H. K. Sandia National Laboratories. SURFTHERM is a Fortran program (surftherm.f) that is used in combination with CHEMKIN (and SURFACE CHEMKIN) to aid in the development and analysis of chemical mechanisms by presenting in tabular form detailed information about the temperature and pressure dependence of chemical reaction rate constants and their reverse rate constants, reaction equilibrium constants, reaction thermochemistry, chemical species thermochemistry, and transport properties. 

CHEMKIN REAL-GAS A Fortran Package for Analysis of Thermodynamic Properties and Chemical Kinetics in Nonideal Systems, Schmitt, R. G., Butler, P. B. and French, N. B. The University of Iowa, Iowa City, IA. Report UIME PBB 93-006,1993. A Fortran program (rglib.f and rgin-terp.f) used in connection with CHEMKIN-II that incorporates several real-gas equations of state into kinetic and thermodynamic calculations. The real-gas equations of state provided include the van der Waals, Redlich-Kwong, Soave, Peng-Robinson, Becker-Kistiakowsky-Wilson, and Nobel-Abel. 

CHEMClean and CHEMDiffs The Comparison of Detailed Chemical Kinetic Mechanisms Application to the Combustion of Methane, Rolland, S. and Simmie, J. M. Int. J. Chem. Kinet. 36(9), 467 471, (2004). These programs may be used with CHEMKIN to (1) clean up an input mechanism file and (2) to compare two clean mechanisms. Refer to the website http //www. nuigalway.ie/chem/c3/software.htm for more information. 

MECHMOD A utility program written by Turanyi, T. (Eotvos University, Budapest, Hungary) that manipulates reaction mechanisms to convert rate parameters from one unit to another, to calculate reverse rate parameters from the forward rate constant parameters and thermodynamic data, or to systematically eliminate select species from the mechanism. Thermodynamic data can be printed at the beginning of the mechanism, and the room-temperature heat of formation and entropy data may be modified in the NASA polynomials. MECHMOD requires the usage of either CHEMK1N-TT or CHEMKIN-III software. Details of the software may be obtained at either of two websites http //www.chem.leeds.ac.uk/Combustion/Combustion.html or http //garfield. chem.elte.hu/Combustion/Combustion. html. 

CONP Kee, R. J., Rupley, F. and Miller, J. A. Sandia National Laboratories, Livermore, CA. A Fortran program (conp.f) that solves the time-dependent kinetics of a homogeneous, constant pressure, adiabatic system. The program runs in conjunction with CHEMKIN and a stiff ordinary differential equation solver such as LSODE (lsode.f, Hindmarsh, A. C. LSODE and LSODI, Two Initial Value Differential Equation Solvers, ACM SIGNUM Newsletter, 15, 4, (1980)). The simplicity of the code is particularly valuable for those not familiar with CHEMKIN. 

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