【摘要】 针对航空煤油发动机在中低负荷工况动力特性差以及燃烧稳定性差难以满足起飞要求这两个突出问题,以自主研发的低压空气辅助直喷航空煤油发动机及其试验系统为平台,采用试验设计(design of experiment,DOE)方法,对喷气脉宽、喷气压力、油气间隔、二次喷射等多个喷油控制参数进行了主效应及交互作用分析,并根据主效应及交互作用顺序进行了多喷油参数协同控制,开展了对航空煤油发动机动力性及燃烧特性影响的试验探究。结果表明:随着喷气脉宽增加,燃烧速度逐渐加快,排温持续下降,动力性及燃烧稳定性逐渐提升。喷气压力与喷气脉宽协同控制能够有效提升发动机整体性能,在喷气压力550 kPa、喷气脉宽5 ms时,平均有效压力(indicated mean effective pressure,IMEP)达到当前最大值529 k Pa,燃烧质量最佳。随着油气间隔逐渐增大,各喷气压力条件下发动机动力性及燃烧稳定性均呈先提升后减小趋势,油气间隔与喷气压力协同控制能够在最佳喷气脉宽条件下进一步提升发动机整体性能,且存在最佳油气间隔为1.5 ms。在最佳油气间隔与喷气脉宽条件下,二次喷射与喷气压力协同控制能够进一步使发动机动力特性最大提升11.3%、燃烧稳定性最大增强23%,排温降至最低702℃,使航空煤油发动机动力特性以及燃烧稳定性得到有效提升。更多还原

【Abstract】 Aviation kerosene engine has poor dynamic characteristics and poor combustion stability under low and medium load conditions,which makes it difficult to meet the takeoff requirements. To address these issues,taking the self-developed low-pressure air-assisted direct-injection aviation kerosene engine and its test system as a platform and adopting the design of experiment method,the main effects and interactions of several injection control parameters,such as jet pulse width,jet pressure,fuel-air interval,and dual injection,were analyzed. According to the order of the main effects and interactions,multiple fuel injection control parameters were collaboratively controlled to test the dynamic and combustion characteristics of the aviation kerosene engine. Results show that,with the increase in jet pulse width,the combustion speed gradually accelerates,the exhaust temperature continuously decreases,and the power and combustion stability gradually increase. The coordinated control of jet pressure and jet pulse width can effectively improve the overall performance of the engine. When the jet pressure is 550 kPa and the jet pulse width is 5 ms,the indicated mean effective pressure reaches a maximum of 529 kPa and the best combustion quality. With the gradual increase in fuel-air interval,the power and combustion quality of the engine tend to initially increase and subsequently decrease under various jet pressure conditions and the optimal fuel-air interval of 1.5 ms.The coordinated control of the fuel-air interval and jet pressure can further improve the overall engine performance under the optimal jet pulse width condition. Under the optimal fuel-air interval and jet pulse width conditions,the cooperative control of dual injection and jet pressure further increases the power of the engine by 11.3% and the combustion stability of the engine by 23% and decreases the exhaust temperature to a minimum of 702 °C,thereby effectively improving the dynamic characteristics and combustion stability of the aviation kerosene engine.更多还原