Modeling and analysis of supercritical hydrocarbon fuel heat and mass transfer with catalytic steam reforming

Regenerative cooling technology is crucial for addressing the severe thermal protection challenges faced by engines in hypersonic vehicles. The steam reforming reaction of hydrocarbon fuels is an effective method for significantly enhancing the fuel's heat absorption capacity. Current research has not fully examined the correlation of convective heat transfer coefficients and their relationship with the endothermic capacity of steam reforming reactions. In this study, the catalyst coating is simplified as a surface with no thickness, and a multidimensional numerical simulation model for the steam reforming reaction of n-decane at supercritical pressure is proposed, applicable under constant wall heat flux. The model has been validated against experimental results, showing a maximum relative error in fuel conversion of 12 %. Gnielinski correlation is tested to be applicable for convective heat transfer predictions in range of 7000 ≤ Re ≤ 180,000, and fuel conversion less than 20 %. An augmentation ratio, defined as the ratio of total to physical heat sink increase per unit tube length, is introduced. Using this ratio, the predicted total heat transfer coefficient shows a deviation of no more than 16 %.