Experimental results of convection heat transfer to supercritical hydrocarbon fuel (RP-3) in heated vertical tubes were reported in this paper.The effects of heat flux

inlet temperature and flow direction (upward and downward) on heat transfer were studied.In the experiments

the pressure and mass flow rate were maintained at 5MPa and 3g/s the respectively;the heat flux changed from 300kW/m2 to 600kW/m2 and the inlet temperature ranged from 293K to 673K.Test results indicate that heat transfer deterioration appears firstly at the inlet of the heated test section and then increases after thermal boundary layer is developed totally.In addition

heat transfer is enhanced near the critical point of the fuel due to the significant changes of thermalphysics properties;when the inlet temperature of RP-3 exceeds its pseudo-critical temperature

heat transfer deterioration occurs again due to the heat capacity of RP-3 decreases rapidly

Furthermore

the heat transfer coefficient of RP-3 in downward flow is greater than that in upward flow due to the buoyancy effect even if the value of determining factor is lower than 10-5.Based on the experimental data

correlations are developed for the local Nusselt number of convection heat transfer to supercritical hydrocarbon fuel in vertical miniature heated tubes.