Numerical Study of Pressure Effect on Deterioration in Heat Transfer with Supercritical Hydrocarbon Fuel

In order to study the pressure effect on heat transfer deterioration of supercritical hydrocarbon fuel in vertical tube, numerical method with four component surrogate model of RP-3 and LS low Reynolds turbulence model was carried out, buoyancy force and physical properties were focused to analyze mechanism of pressure effect, meanwhile comparisons between pipes of diameter 2mm and 10mm were done. The numerical results on wall temperature distribution under various conditions were compared with experimental data and a good agreement was obtained. Results of the research suggest that when pressure increase to 5MPa without concerning decomposition and coking, the change of physical properties tends to be gentle, the inhomogeneity of density and specific heat are alleviated, average of specific heat increases as well, which all make heat transfer deterioration alleviated. But in the pipe of diameter 10mm, fluid inside is harder to be heated and temperature difference between pipe wall and pipe axis is up to 300K, which leads to the increase of property inhomogeneity, pressure effect of alleviating heat transfer deterioration is weakened.