Investigation into Effect of Residence Time on Cooling Characteristics of RP-3

Efficient utilization of chemical heat sinks and enhancement of heat transfer are key issues for the thermal protection of advanced hypersonic flight vehicles. However, the influences of residence time on the pyrolysis and convection heat transfer of hydrocarbon fuel are different, which is important for the design and optimization of cooling systems. Therefore, a multidimensional numerical simulation model based on a molecular reaction model of aviation kerosene, RP-3, is established. This model reveals that the residence time has a great influence on the heat sink and heat transfer characteristics under the supercritical condition. With the increase of the residence time, the chemical heat sink and physical heat sink increase, whereas the convective heat transfer coefficient decreases. The heat transfer is not only affected by flow structures but also by the ratio of the chemical heat sink to the physical heat sink. With the increase of the residence time, this ratio first increases and then decreases. It has a maximum value, and the residence time corresponding to this maximum value is exactly the residence time when the total chemical heat sink rate reaches the maximum. A correlation predicting the maximum heat sink ratio is proposed based on these data.