Two-dimensional combustion modeling of heterogeneous solid propellants with finite Peclet number

A combustion model has been formulated to solve the burning rate eigenvalue problem for a model heterogeneous solid propellant (two-dimensional sandwi ch) with Peclet number of O(1), similar to what has been done previously fo r homogeneous energetic solids. A two-step reaction sequence (high-activati on-energy, condensed-phase decomposition followed by low-activation-energy, gas-phase heat release) has been extended from one to two dimensions for n onpremixed (heterogeneous fuel/oxidizer) composite solids. Gas-phase stream wise diffusion, the primary driving force for solid pyrolysis, has been acc ounted for by including a finite value of the Peclet number. The results sh ow that the value of the Peclet number, a nondimensional burning rate, is c onstrained to a reasonably small interval by the eigenvalue expression obta ined from activation energy asymptotic analysis of the condensed-phase ther mal decomposition zone. These results demonstrate the feasibility of and ge neral approach for solving the two-dimensional composite propellant burning rate as an eigenvalue problem. (C) 2000 by The Combustion Institute.