On assessment of heat transfer deterioration of a channel with supercritical n-decane for scramjet engines cooling

To explore the local heat transfer deterioration (HTD) behavior in cooling channels with the endothermic hydrocarbon fuel for a scramjet engine, the flow and thermal performance of a rectangular channel cooled by supercritical hydrocarbon fuel are analyzed in detail, especially at the region of the heated wall. A 3D geometrical model is simulated under a SST k-ω turbulence model to validate results which agrees well with available experimental data. The critical variations of turbulent kinetic energy and representative thermo-physical properties are selected to assess the internal mechanism of HTD in terms of the deteriorative point of the wall temperature and the heat transfer coefficient. This study reveals that the occurrence of HTD is strongly affected by the variation of turbulent kinetic energy, and that the local HTD behavior is considered to be induced by the laminar flow caused by thermal acceleration effect.