Modelling reaction propagation for Al/CuO nanothermite pellet combustion

摘要

A continuum-scale model for the combustion of consolidated nanothermite pellets is introduced. A simplifiedchemical kinetics model is used for the solid state nanothermite reaction while a two-phaseporous media flow accounts for the mass and heat transfer within the consolidated pellet under anequilibrium thermodynamic assumption. The thermophysical and chemical kinetic properties of theAl/CuO nanothermite pellets are determined from the literature. A sensitivity analysis reveals the relativeimportance of these modelling parameters for both the advection and conduction-dominated combustionregimes. Based on the governing equations, we propose a thermodynamically consistent nondimensionalizationof the global Peclet and Damk?hler numbers which are based on the characteristicDarcy velocity within the porous pellet. The non-dimensionalization results in a linear scaling betweenthe normalized burn rate and Peclet number, which allows a collapse of the numerical results with publishedexperimental data. We identify a transition between the conduction- and advection-dominatedcombustion based on the transient burn rate of the nanothermite pellet combustion.