Premium
Burning rates of solid propellants
Author(s) -
Smith J. M.
Publication year - 1960
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690060225
Subject(s) - propellant , ammonium perchlorate , thermodynamics , combustion , chemistry , diffusion , heat transfer , chemical reaction , reaction rate , activation energy , organic chemistry , physics , catalysis
A model is proposed for the burning of solid propellants which takes into account heat transfer, diffusion, and chemical reaction processes. The chemical step influencing the rate is postulated to be a reaction between a gaseous molecule and a solid component occurring at the solid‐gas interface. The combination of expressions for the rates of the heat transfer, diffusion, and reaction steps leads to relatively simple equations for the burning rate in terms of (1) the physical properties of the propellant; (2) the transport coefficients; (3) the operating conditions of the burning process, temperatures, and pressure; and (4) chemical characteristics of the gas‐solid reaction, activation energy, frequency factor, and heat of reaction. The well‐established facts concerning burning rates, the effect of pressure and initial temperature, and the phenomenon of erosive burning are predicted by the proposed theory. Also specific experimental data for burning potassium and ammonium perchlorate composite propellants can be predicted from the theory. The values of the variables necessary to obtain agreement between observed and predicted results are generally realistic. However it should be emphasized that conclusions regarding the detailed mechanism of the burning process cannot be obtained from comparison with burning‐rate data. Elucidation of the kinetic steps in the process will require experimental investigation of the intermediate products of combustion and a detailed study of the burning surface and gaseous flame zone.