Coupling relationship analysis between flow and pyrolysis reaction of endothermic hydrocarbon fuel in view of characteristic time correlation in mini-channel

Abstract

In order to study the coupling relationship between flow and pyrolysis of endothermic hydrocarbon fuel in mini-channel of regeneratively cooled advanced aeroengines, characteristic time was defined to describe the time scales for flow and pyrolysis reaction in pyrolysis reaction flow field. The DamkÖhler number (Da) was used to quantitatively describe the relationship and degree of coupling between flow and pyrolysis reaction in mini-channel in terms of characteristic time. A 1D model was established to describe the coupling relationship of flow and pyrolysis reaction, and validated through experimental data. Simulation and experimental results indicated that: relationship and degree of coupling between flow and pyrolysis reaction could be quantitatively described using Da. The flow field could be divided into three regions according to the distributions of Da and chemical heat sink: frozen flow, non-equilibrium flow and equilibrium flow. Each region exhibited the different coupling characteristics between flow and pyrolysis reaction, which resulted in different distribution of chemical heat sink. There was a maximum rate of chemical heat sink releasing between non-equilibrium region and equilibrium region in particular. And the variation of flow had no influence on the maximum rate of chemical heat sink releasing.