空气辅助雾化对活塞式航空煤油发动机燃烧特性的影响研究

Effects of Air-Assisted Atomization on Combustion Characteristics of Piston Aviation Kerosene Engine

关键词:  空气辅助喷射  航空煤油  活塞式发动机  喷射参数  燃烧特性

Key words:  Air-assisted injection  Aviation kerosene  Piston engine  Injection parameters  Combustion characteristic

摘要:

为了满足无人机燃料的安全性、单一化战略，并实现发动机高功重比指标，将航空煤油应用在点燃式活塞发动机上，使用自主开发的空气辅助喷雾系统，在节气门全开条件下进行了不同过量空气系数、喷气压力、喷气脉宽、喷射时刻对于活塞式航空煤油发动机燃烧特性的影响研究，并将空气辅助雾化系统和120MPa高压共轨系统进行对比试验。结果表明，0.95为活塞式航空煤油发动机的最佳过量空气系数；提高喷气压力和喷气脉宽均会提高发动机的动力性和经济性，提高燃烧稳定性，并且提高喷气压力可以明显缩短燃烧持续期；360°CA BTDC喷气时刻时航空煤油的雾化效果最好；喷射参数优化后的空气辅助雾化系统对于航空煤油的雾化效果接近高压共轨系统水平。

Abstract:

In order to meet the safety and simplify strategy of UAV fuel， and to achieve the high power-weight ratio index of the engine， aviation kerosene is applied to the ignition piston engine in this paper. Using the self-developed air-assisted spray system， the effects of different excess air coefficient， air injection pressure， air injection pulse width and injection time on the combustion characteristics of piston aviation kerosene engine were studied under the condition of fully open throttle. And the comparative test was conducted between the air-assisted spray system and 120MPa high pressure common rail system.The results show that 0.95 is the optimal excess air coefficient of piston aviation kerosene engine.The performance of power， economy and combustion stability of the engine will be improved by increasing the air injection pressure and pulse width， and increasing air injection pressure can significantly shorten the combustion duration. The atomization effect of aviation kerosene is the best at 360°CA BTDC air injection time. The atomization effect of air assisted atomization system with optimized injection parameters for aviation kerosene is close to the level of high-pressure common rail system.