| Abstract:In order to improve the combustion thermal efficiency of aviation kerosene in spark ignition engine, suppress knock and broaden engine load range, a single-cylinder water-cooled, four-stroke gasoline engine of adjustable compression ratio was used together with high pressure common rail direct injection technology to study the effects of single and twin sparks, different loads, different compression ratios, different injection pressures, different injection timings, and split injection on the combustion performance of aviation kerosene. The results show that, when the compression ratio of 10 of the base engine is kept and the direct injection of gasoline is replaced by the direct injection of RP-3, the engine power loss is by about 50%, the fuel consumption rises by about 60%, and the cycle fluctuation increases greatly due to the low octane number, poor atomization and slow combustion rate of the aviation kerosene. Compared with the single-spark, the twin-spark can enhance the mean effective pressure in cylinder and combustion phase. In order to avoid the knock tendency at high compression ratios and widen the load range, the compression ratio is reduced, raising the engine power close to the base engine level. With the decrease of the compression ratio, the brake mean effective pressure continues to increase. When the compression ratio is reduced to 6, the optimal torque can reach 39.5 N·m, restoring 88% of the base engine power. Meanwhile, the effective fuel consumption can be reduced by about 30% by coupling high pressure and split injection strategy, improving fuel economy. Compared with the single-injection, the split injection strategy can reduce the fuel consumption, increase the mean effective pressure in cylinder, and promote the combustion efficiency, which enables the engine using aviation kerosene to achieve the performance close to the base engine level. |