Simulation of reactive nanolaminates using reduced models: III. Ingredients for a general multidimensional formulation

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2009.10.005· OSTI ID:21318366

Salloum, Maher; Knio, Omar M ^[1]

---

1. Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218-2686 (United States)

A transient multidimensional reduced model is constructed for the simulation of reaction fronts in Ni/Al multilayers. The formulation is based on the generalization of earlier methodologies developed for quasi-1D axial and normal propagation, specifically by adapting the reduced formalism for atomic mixing and heat release. This approach enables us to focus on resolving the thermal front structure, whose evolution is governed by thermal diffusion and heat release. A mixed integration scheme is used for this purpose, combining an extended-stability, Runge-Kutta-Chebychev (RKC) integration of the diffusion term with exact treatment of the chemical source term. Thus, a detailed description of atomic mixing within individual layers is avoided, which enables transient modeling of the reduced equations of motion in multiple dimensions. Two-dimensional simulations are first conducted of front propagation in composites combining two bilayer periods. Results are compared with the experimental measurements of Knepper et al., which reveal that the reaction velocity can depend significantly on layering frequency. The comparison indicates that, using a concentration-dependent conductivity model, the transient 2D computations can reasonably reproduce the experimental behavior. Additional tests are performed based on 3D computations of surface initiated reactions. Comparison of computed predictions with laser ignition measurements indicates that the computations provide reasonable estimates of ignition thresholds. A detailed discussion is finally provided of potential generalizations and associated hurdles. (author)

• OSTI ID: 21318366
• Journal Information: Combustion and Flame, Vol. 157, Issue 6; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
EQUATIONS OF MOTION
SIMULATION
COMPARATIVE EVALUATIONS
THERMAL DIFFUSION
LAYERS
CALCULATION METHODS
HEAT
TRANSIENTS
IGNITION
MIXING
TWO-DIMENSIONAL CALCULATIONS
RUNGE-KUTTA METHOD
THREE-DIMENSIONAL CALCULATIONS
STABILITY
VELOCITY
NANOSTRUCTURES
NICKEL
ALUMINIUM
REACTION KINETICS
Reactive multilayers
Reduced model
Self-propagating reactions
Multidimensional simulation