Quasi-steady combustion modeling of homogeneous solid propellants

Journal Article · Sun Oct 01 00:00:00 EDT 1995 · Combustion and Flame

DOI:https://doi.org/10.1016/0010-2180(95)00075-H· OSTI ID:116455

Brewster, Q ^[1]; Son, S F ^[2]

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1. Univ. of Illinois, Urbana, IL (United States). Dept. of Mechanical and Industrial Engineering
2. Los Alamos National Lab., NM (United States)

Classical, linearized quasi-steady (QS) theory of unsteady combustion of homogeneous solid propellants (both pressure- and radiation-driven) is reexamined. Zeroth order, high activation energy (E/RT {much_gt} 1), decomposition is assumed. Many prevailing ideas about condensed-phase pyrolysis are challenged and several misconceptions are corrected. The results show the following: (1) the inadequacy of simple Arrhenius surface pyrolysis; (2) that the common assumption of zero Jacobian ({delta} or n{sub s}) parameter is physically unrealistic for pressure-driven combustion except perhaps in plateau regions; (3) that classical quasi-steady theory is not necessarily incompatible with observed pressure instability [Re{l_brace}R{sub p}{r_brace} > 0] in mesa propellants; (4) that measured steady-state combustion parameters (e.g., E{sub c} = 2E{sub s} = 40 kcal/mol for double base propellant) and quasi-steady theory can model T-burner data reasonably well; (5) that the preexponential parameters in the pyrolysis expression play a critical role in the dynamic response (particularly T{sub 0} and Q{sub c}); (6) that thermal radiation also plays an important role through its effect on the steady state sensitivity parameters, particularly the k (or {sigma}{sub p}) parameter. An approach is outlined for modeling dynamic combustion response based on zeroth order pyrolysis which allows difficult parameters, such as r and {delta} (or A and n{sub s}) to be obtained from relatively easily measured ones, k and v (or B and n), E{sub c}, Q{sub c}, and T{sub s}. An approach for determining these fundamental combustion parameters using radiation-driven unsteady burning tests is described.

• OSTI ID: 116455
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 1-2 Vol. 103; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
COMBUSTION INSTABILITY
COMBUSTION KINETICS
COMBUSTION PROPERTIES
KINETIC EQUATIONS
MATHEMATICAL MODELS
PROPELLANTS
SOLID FUELS