Experimental analysis of evaporation and heat transfer characteristics during the ignition process of RP-3 liquid flow on a curved hot surface

• This work focuses on the ignition process of RP-3 flow on a curved hot surface . • Relation of lifetime of RP-3 on a hot surface and the temperature is studied. • Fuel evaporation rate firstly increases to reach a peak, and decreases with time. • Heat proportion from flame to fuel can reach 44.2 % in the ignition process. RP-3 is one of the most widely used aviation fuels in China. The accidental leakage and ignition of RP-3 may pose a serious threat to the aircraft safety. This work focuses on the ignition process of RP-3 liquid flow on a curved hot surface, and investigates characteristics of evaporation and heat transfer. Results showed the flame development after the ignition. There is a small blue flame in the early stage of ignition. Then the blue flame spreads outward from the ignition area to form the yellow flame. A prediction formula for the ignition probability of RP-3 is established. The total lifetime of RP-3 on the curved hot surface is found to decrease as the surface temperature increases. The fuel mass and the fuel evaporation rate on the hot surface are studied. The fuel evaporation rate firstly gradually increases, then reaches a peak value, and finally decreases with the burning time. Based on energy conservation, the heat from the flame to fuel and the heat from the hot surface to fuel are compared in RP-3 injection period and non-injection period. The heat proportion from flame to fuel is found to reach 44.2 % when the curved surface temperature is 660 °C in the injection period. However, this proportion is only within 10% in the non-injection period.