Research on knocking characteristics of kerosene spark-ignition engine for unmanned aerial vehicle (UAV) by numerical simulation

The favorable physicochemical properties of kerosene have contributed to its widely application in aviation. However, knocking is more prone to take place in kerosene than in gasoline under the same conditions. This paper presents a study on the knock characteristics of a ROTAX914 engine that is fueled by kerosene. The knocking combustion process was simulated under various engine operating conditions. The effect of engine ignition timing, exhaust gas recirculation (EGR), and mixture concentration on the engine knocking combustion were studied based on a three-dimensional simulation. The results showed that engine knock could be effectively suppressed by delayed ignition timing. With increased EGR rates, knocking intensity was greatly suppressed.