Gasification of multi-layer porous fuels in low-temperature gas generator for flying vehicle

•New numerical model for studying the gasification of multi-component porous fuels is developed.•Effect of the layering of solid porous fuels on their gasification is investigated.•During the gasification of multi-layer fuels, several gasification waves can occur simultaneously.•Operating time of the gasifier depends on the relative position of the fuel layers.•Relative sizes of the layers and their relative arrangement can be control parameters. The paper is aimed at investigating the influence of porous fuel layering on the operating regimes and performance of a low-temperature gas generator for high-speed flying vehicles equipped with a ramjet engine. The gas generator consists of a propellant and a porous fuel arranged sequentially to generate hydrocarbon gases that cool the engine before burning in the combustion chamber. In this paper, using a novel numerical model, gasification of multi-layer solid porous fuels consisting of polymethylmethacrylate (PMMA) and polyethylene (PE) is studied for various volume contents and relative arrangements of fuel parts. It is shown that during the gasification of the multi-layer fuels, several gasification waves can simultaneously occur in the gas generator. The operating time of the gas generator depends on the relative sizes and relative location of the PMMA and PE layers, and an increase in the number of layers leads to a decrease in the influence of their relative arrangement on the process. Thus, during the gasification of two-component multi-layer solid porous fuel, the composition of this fuel, i.e., the relative sizes of the layers and their relative arrangement, can be the control parameter that allows one to choose the desired characteristics of the gasification process.