Chemistry and Thermodynamics ::
Chemical Equilibrium with Transport Properties
Scientists and engineers need chemical equilibrium composition data
to calculate the theoretical thermodynamic properties of a chemical system.
This information is essential in the design and analysis of equipment such as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical processing equipment. For more than 40 years the NASA Lewis Research Center has been involved in developing methods and computer programs for calculating complex chemical equilibrium compositions and thermodynamic and transport properties of the equilibrium mixtures and for applying these properties to a number of problems. The latest version of these programs is CET93. CET93/PC is a version of CET93 which is specifically designed to run within the 640K memory limit of the MS-DOS operating system.
CET93/PC is a general program which will calculate chemical equilibrium
compositions and mixture properties for any chemical system with
available thermodynamic data. Generally, mixtures may include condensed
and gaseous products. CET93/PC performs the following operations:
CET93/PC includes a file of thermodynamic data for over 1100 gaseous
and condensed species and a file of thermal transport property data for
155 gaseous species. These data are in the form of least squares coefficients
in binary form. Through use of a new "ONLY" option users may instruct
CET93/PC to consider only particular species as possible products for a
given equilibrium composition calculation. Relative to CET93, CET93/PC
has a few limitations on array size so that it will run within the basic 640K
of random access memory (RAM) available under MS-DOS. The maximum number of
possible reaction species accommodated for any chemical system was reduced
from 600 to 300, and the maximum number of condensed reaction species was
reduced from 300 to 200. Experience has shown, however, that these limits
are sufficient for most practical chemical systems.
obtains chemical equilibrium compositions for assigned thermodynamic
- calculates dilute-gas transport properties of complex chemical
- obtains Chapman-Jouguet detonation properties for gaseous
- calculates incident and reflected shock properties in terms of
assigned velocities, and
- calculates theoretical rocket performance for
both equilibrium and frozen compositions during expansion. The rocket performance
function allows the option of assuming either a finite area or an
infinite area combustor.
CET93/PC is written in FORTRAN and is available only as executable code
for use on IBM PC series and compatible computers running MS-DOS. The executable
was created using Microsoft FORTRAN 5.1 on a 386SX PC without a math
coprocessor; however, the executable will take advantage of a math coprocessor
when one is present. At least 400K of RAM must be available for this
executable to run properly. The distribution medium for CET93/PC includes
input and output files for the example problems and two files describing
how to use the program. The hardcopy documentation for CET93/PC consists
of a copy of these instructions plus NASA Technical Memorandum 4557, which
includes a listing of the species names of possible products.
CET93/PC carries the NASA case number LEW-16017. It was originally released as part of the NASA COSMIC collection.
More software from National Technology Transfer Center