Flow and mass transfer of pyrolytic aviation kerosene in curved channel

Surface coking is significantly affected by the mass transfer of regenerative cooling system in advanced aeroengines. On the basis of the detailed chemical kinetic mechanism of China No. 3 jet fuel (also known as RP-3), the flowfield and surface coking of RP-3 in the curved cooling channel surrounding around the cavity flameholder of scramjet are numerically studied. Results indicate that the vortex structure enhances the fluid mixing in the curved cooling channel, and so it improves heat and mass transfers between near-wall region and core flowfield. Compared with the straight cooling channel, the curved cooling channel has higher fuel conversion and thinner thermal boundary layer, but less concentration of coking precursors in near-wall region. The vortex structure can effectively promote fuel pyrolysis and inhibit coke deposition in curved channels. In addition, with the increase of inlet Reynolds number, more coking precursors in near-wall region are moved toward core flowfield. The increasing inlet Reynolds number enhances mass transfer and inhibits carbon deposition in the curved cooling channel. Results in this paper provide significant guidance for design and optimization of regenerative cooling technology in advanced engines.