Ignition, efficiency and emissions of RP-3 kerosene in a three-staged multi-injection combustor

In this work, a three-staged multi-injection based on the triple-swirler technique was proposed and investigated, which can broaden the engine envelope than a two-staged fuel supply scheme. The fuel can be split into three portions according to the combination of different injectors. Injection-1 means that only injector-1 supplies fuel, while Injection-1 + 2 means that injector-1 and injector-2 supply fuel simultaneously. The spark ignition performance, combustion efficiency, and exhaust emissions by using RP-3 kerosene are analyzed and compared with different fuel injection modes. The excellent ignition performance is achieved by using injection-1 with the ignition fuel-air ration is 0.008, whereas the other injection modes perform relatively poorly. The efficiency and exhaust emissions curves achieved by injection-1 + 2 and injection-1 + 3 intersect, where the overall equivalence ratio is about 0.25. When the overall equivalence ratio exceeds this critical value, the combustion efficiency of RP-3 kerosene achieved by using injection-1 + 3 can be up to 1% higher than injection-1 + 2. Furthermore, the optimal fuel supply scheme by the three-staged multi-injection technology is achieved: injection-1 is used for spark-ignition, injection-1 + 2 for low power conditions (overall equivalence ratio is less than 0.25), and injection-1 + 3 for high power conditions.