The injection of supercritical RP-3 aviation kerosene fuel into a quiescent atmospheric environment was experimentally investigated to study the jet structures and phase transition process near the nozzle exit.It was found that supercritical kerosene jets injected above the critical point underwent ideal-gas-like expansion and exhibited visible Mach disk shock structures.The axial location of the Mach disk increased with the injection pressure

and the injection temperature had little effects on the axial location of Mach disk.The phase transition process analysis revealed that the supercritical kerosene fuel was penetrated into the gas region from the supercritical region directly at the nozzle exit

without going through two-phase region at higher injection temperature.Fuel condensation phenomenon occurred in the nozzle and fuel entered two-phase region when fuel was injected near the critical point.