This paper reports the results of numerical studies carried out for a periodic sandwich propellant geometry with two-dimensional unsteady gas and condensed phase. A non-planar regressing surface along with a kinetic model of two reaction steps in the gas phase was used. This paper discusses the importance of lateral momentum equation to the combustion of sandwich propellants. It demonstrates that the instabilities in sandwich combustion reported in literature are due to neglect of lateral momentum equation and incorrect boundary conditions at the regressing surface. It demonstrates that neglect of momentum equations will lead to a different result from the one obtained considering the momentum equations for sandwich propellants. © 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Periyapatna A. Ramakrishna

Department of Aerospace Engineering

Momentum

Propellants

Combustion model

Condensed phase

Gasphase

Kinetic modeling

LATERAL MOMENTUM

Momentum equation

REACTION STEPS

combustion

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Proceedings of the Combustion Institute

The two-dimensional flow field in the vicinity of the interface between laminae of a solid oxidizer and solid fuel under steady-state conditions is solved for empirical inputs, taking into account the nonplanarity of the burning surfaces of the two laminae. The experimentally observed nonplanar burning surface under steady-state conditions is used to prescribe the upstream boundary conditions to the gas phase domain. The regression rate of the burning surface along the laminar interface, determined experimentally, is also used as an input. This decouples the condensed phase energy balance from the gas phase fluid dynamics, and assigns the distribution of surface temperature along the burning surface. The equation for two-dimensional energy conservation in the condensed phase is also solved, with the heat flux balance giving a boundary condition across the burning surface. A distribution of heat release rate is assumed in the gas phase, and the gas phase energy equation is solved iteratively with a convergence criterion set by the interfacial heat flux balance across the burning surface. This obviates the need for a knowledge of the chemical kinetic details of the gas phase flame. The goal is to determine a realistic distribution of heat release rate which satisfies the burning surface profile and its regression rate, measured for a laminar system of ammonium perchlorate and polymethyl methacrylate at pressures below the self-deflagration limit of the former. The results indicate lateral heat conduction in the condensed phase from the oxidizer lamina to the fuel lamina. The computed distribution of heat release rate in the gas phase indicates the need to include heat release near the surface, as well as farther downstream at typical stand-off distances for the flame. © 2003 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Combustion and Flame

Combustion at the interface of a laminate system of solid oxidizer and solid fuel

Corrigendum to “Sandwich propellant combustion: Modelling and experimental comparison” [Proc. Combust. Inst. 29 (2002) 2963–2973]

Aerospace Science and Technology

Modeling unsteady and perturbed combustion of heterogeneous composite propellants

Numerical simulation of the 3-dimensional combustion of aluminized heterogeneous propellants

AP/HTPB laminate propellant flame structure: Fuel-lean intrinsic instability

Importance of lateral momentum equation to the modeling of sandwich propellant combustion

Journal	Data powered by TypesetProceedings of the Combustion Institute
Publisher	Data powered by TypesetElsevier Ltd
ISSN	15407489
Open Access	No