Computer program numerically solves nonlinear algebraic equations for chemical equilibrium based on iteration equations independent of choice of components. This program calculates theoretical performance for frozen and equilibrium composition during expansion and Chapman-Jouguet flame properties, studies combustion, and designs hardware

Gordon, S.

Zeleznik, F. J.

English

NASA Technical Reports Server

December 1966
	 Brief 66-10671 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Computer Program Determines Chemical Equilibria in Complex Systems 
The problem: 
To solve numerically, nonlinear algebraic equations 
describing chemical equilibria in complex systems. 
The solution: 
A computer program for chemical equilibrium 
computations based on iteration equations that are 
independent of choice of components. 
How it's done: 
The NASA Lewis Research Center has developed 
a computer program for the IBM 7090 or 7094 
written in FORTRAN IV for the computation of 
chemical equilibria in complex systems with several 
applications. The program permits iteration equations 
to be written in a form independent of the choice of 
components. The program can perform the following 
calculations: 
1. chemical equilibrium for assigned temperatures 
and pressures, 
2. theoretical rocket performance for both frozen 
and equilibrium composition during expansion; 
and 
3. Chapman—Jouguet detonation properties. 
The objective has been to develop a program that 
can compute equilibrium compositions for any chemi-
cal system for which thermodynamic data exist. To 
accomplish this objective, several special techniques 
were incorporated to handle problems that would 
otherwise not converge. These techniques, which have 
proven successful in the many problems attempted, 
include a flexible convergence control parameter and 
automatic inclusion of condensed species with the
possibility of triple points. A discussion of some of 
the problems attendent with the presence of con-
densed species as reaction products is also given. 
Notes: 
1. The following are some of the program's general 
features: It requires only a simple input and no 
initial estimates. It handles up to 15 chemical 
elements and a total of 90 reaction products in-
cluding condensed species. 
2. The computer program can be used to analyze 
and study combustion processes and design hard-
ware such as furnaces, combustion engines, chem-
ical reactors, etc. 
3. Additional information is contained in NASA 
Technical Note D-1454, "A General IBM 704 or 
7090 Computer Program for Computation of 
Chemical Equilibrium Compositions, Rocket Per-
formance, and Chapman—Jouguet Detonations," 
by F. J. Zeleznik and Sanford Gordon, October 
1962. Inquiries concerning this innovation may 
also be directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B66-10671 
Patent status: 
No patent action is contemplated by NASA. 
Source: Frank J. Zeleznik and Sanford Gordon 
(Lewis-281) 
Category 01 
This document was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19660000669 2020-03-11T17:43:02+00:00Z


Computer program determines chemical equilibria in complex systems

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server