Effects of hydrogen addition on burning characteristics of RP-3 kerosene

In order to illustrate the effects of hydrogen addition on the combustion characteristics of RP-3 kerosene, the laminar burning velocity and Markstein length of RP-3 kerosene/hydrogen mixture were investigated experimentally in a constant volume combustion bomb. The experiments were performed at initial pressure of 0.1MPa, initial temperatures of 390,420K and over the equivalence ratios range of 0.8-1.5. The influences of hydrogen addition ratio on the flame structure, laminar burning velocity and Markstein length were investigated. Results showed that some cracks or folds appeared on the flame front in the flame developing process, and the instability of flame increased with the growing hydrogen addition ratio. Increasing the equivalence ratio or the hydrogen addition ratio decreased the Markstein length of RP-3 kerosene/hydrogen mixture. Furthermore, with the equivalence ratio increasing from 0.8 to 1.5, the laminar burning velocity of RP-3 kerosene/hydrogen mixture increased initially and then decreased gradually. The highest laminar burning velocity was measured at fuel rich condition (the equivalence ratio was 1.2). At the same time, with the increase of initial temperature or hydrogen addition ratio, the laminar burning velocity of RP-3 kerosene/hydrogen mixture showed an increasing trend.