NASA polynomials coefficients

PRINT OUT THE NASA POLYNOMIAL COEFFICIENTS AGAIN IN A COUPLE OF USEFUL FORMATS. YOU WILL NEED THESE FORMATS TO CONSTRUCT NASA-TYPE DATA CARDS HOLDING TWO SETS OF COEFFICIENTS, I.E. ONE SET FOR 300 TO 1000 K AND ONE SET FOR ABOVE 1000 K. 

The ThermKin code described in chapter 2 is used to determine the elementary reaction rate coefficients and express the rate coefficients in several Arrhenius forms. It utilizes canonical transition state theory to determine the rate parameters. Thermodynamic properties of reactants and transition states are required and can be obtained from either literature sources or computational calculations. ThermKin requires the thermodynamic property to be in the NASA polynomial format. ThermKin determines the forward rate constants, k(T), based on the canonical transition state theory (CTST). 

This computer program calculates the coefficients of the NASA polynomials from thermodynamic data supplied by the user. 

The seven-coefficient NASA polynomials can be used to calculate the following functions ... 

In combustion systems, thermodynamic properties are often calculated from 14 fitted polynomial coefficients called the NASA polynomials for each species (Burcat 1984). Seven are used for the low-temperature range Tiow to and seven... 

As well as rate coefficient information, thermodynamic data are required for the description of many chemical systems. A number of software packages are available to calculate thermodynamic data such as THERM (Ritter and Bozzelli 1991) or THERGAS (Muller et al. 1995). NASA polynomials are often used as a starting point for the calculation of thermod3niamic properties (see Sect. 2.2.3) and have been made available for many years via the data base of Alexander Burcat (Burcat 1984 Burcat and Ruscic 2005 Burcat) as well as in recent evaluations (Ruscic et al. 2003). 

In the study, the reactions were treated as reversible, with reverse rates calculated from the appropriate equilibrium constants based on enthalpies of formatiOTi calculated using NASA polynomials (see Sect. 2.2.3). Because so many of the input parameters were estimated, derived from a low number of measurements or from single theoretical studies, the input distributions were cmisidered to be uniform between predefined minimum and maximum values (Tomlin 2006). Uncertainties in the rate coefficients were expressed using A-factors only, since for most reactions, there was insufficient information to determine the joint of the Arrhenius parameters. 

Most of the JANAF tables have been fitted to polynomials by the NASA thermodynamics group. Polynomial coefficients for the species included in the main JANAF volume (1971) have been published (Gordon and McBride, 1971) and are supplied with the NASA SP-273 computer program. 

First, the literature should be searched for spectroscopic data, and if these are sufficient, the thermodynamic properties can be calculated by statistical mechanics formulas. McBride and Gordon s program (1967) is recommended for this purpose. The latest verson, PAC3, includes, among many possible calculation methods, an accurate calculation method for internal rotation contributions, which are important when organic species are involved, and a subroutine which automatically calculates the coefficients of the NASA polynomials. Wilhoit s extrapolation method was recently included in the code. 

Wakelyn, N.T. McLain, A.G. (1975). Polynomial Coefficients of Thermochemical Data for C-H-O-N Systems, NASA TM X-72657. 

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. 

It is possible to apply the same procedure to NASA nine-term polynomials using as in Eq. (1.41) and accordingly each eigth coefficient in the polynomials for all temperature ranges. 

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