A new approach to thermochemical calculations of condensed fuel-oxidizer mixtures

doi:10.1016/0010-2180(81)90111-5

Combustion and Flame

Volume 40, 1981, Pages 71-79

https://doi.org/10.1016/0010-2180(81)90111-5 Get rights and content

Abstract

A simple method of calculating the elemental stoichiometric coefficient, φ_e has been developed, which can easily be applied to multicomponent fuel-oxidizer compositions. The method correctly predicts whether a mixture is fuel lean, fuel rich, or stoichiometrically balanced. The total composition of oxidizing (or reducing) elements of the mixture appears to be related to the thermochemistry of the system. For the reaction of ammonium perchlorate and an organic fuel the heat of reaction varies linearly with the total composition of oxidizing elements. The physical significance of such a correlation based on thermochemical reasoning is highlighted in the paper.

References (6)

M. Barrere et al.
Rocket Propulsion
N.N. Bakhman
Combust. Explo. Shock Waves
(1968)
T.L. Cottrell et al.
J. Chem. Soc.
(1951)

There are more references available in the full text version of this article.

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A new approach to thermochemical calculations of condensed fuel-oxidizer mixtures

Abstract

Rocket Propulsion

Combust. Explo. Shock Waves

J. Chem. Soc.