Effect of pyrolytic reaction of supercritical aviation kerosene RP-3 on heat and mass transfer in the near-wall region

The high concentration of pyrolytic unsaturated hydrocarbons in the near-wall region will generate surface fouling in the regenerative cooling passage, which dramatically deteriorates heat transfer performance. In the present study, the heat and mass transfer processes are investigated by a numerical method to evaluate the mass distribution of pyrolytic products in the near-wall region. A detailed pyrolysis model of RP-3 aviation fuel is incorporated to analyze the pyrolysis process in the regenerative cooling passage. The results indicate that the enhanced heat transfer performance in reacting flow is attributed to the extra heat-absorbing capacity and the flow acceleration caused by the pyrolytic reaction. Besides, because of flow transition and the ultrahigh wall temperature, the near-wall mass fraction of RP-3 decreases first and then increases at the initial heated section. The concentration of products has a transient peak value, which means there is a high risk of carbon deposition at the initial heated section. In addition, the combined influences of flow transition, wall temperature and mass fraction result in the primary reaction rate experiencing three peaks in the near-wall region when the heat flux reaches 2.5 MW/m².