The impact of fuel ratio and refueling mode on pre-combustion cracking properties of RP-3 kerosene

To achieve kerosene-air rotating detonation without adding hydrogen and oxygen supplement, the pre-combustion cracking of RP-3 kerosene to produce active gas is explored. Effects of fuel ratio (3.2–14.6) and refueling mode on the cracking products distribution are investigated. The effective cracking rate of RP-3 kerosene strongly depends on the fuel ratio, with which kerosene conversion decreases rapidly, and the highest effective cracking rate reaches 92%. In cracking gas, about 26.4% is combustible components, including hydrogen, acetylene, methane, ethylene, carbon monoxide. Among them, carbon monoxide is the highest yield species in the cracking products, reaching 4940 mg/s at the fuel ratio of 3.2. And the highest yields of hydrogen and acetylene are 294 mg/s and 1364 mg/s, respectively. The yield and mole fraction of component decreased obviously with the increase of fuel ratio. In view of the reason that the center temperature of the downstream section is higher, the yield and percentage of component are higher than that when secondary kerosene is injected at the upstream section. Refueling mode has a significant effect on the product distribution, and the mode of refueling with circumferential six nozzles is superior to that of circumferential three nozzles, with which higher component percentage and product mass flow can be obtained. By contrast, the proportion of ethylene in cracking products can be greatly increased by axial refueling mode. Choosing the axial refueling mode at downstream section can obtain higher cracking rate and lower C/H ratio, while choosing the refueling mode with circumferential six nozzles, the content of high active components is more.