点燃式活塞航空重油直喷发动机临界工况燃烧机理的研究

The project will research the combustion mechanism of the heavy fuel piston-type DISI aviation engine under critical conditions systematically with the combined methods of the laser combustion diagnosis, numerical simulation and engine combustion bench tests. The fundamental research are as follows: the heavy fuel mixture spark ignition and rapid combustion mechanism under -20℃ low temperature environment will be conducted systematically, including investigation on heavy fuel spray microstructure and atomization mechanism, mixing rate of heavy fuel mixture by droplet get together in the engine compression stroke, mixture activity innovation and spark ignition energy impact on the in-cylinder fire core formation and flame propagation under -20℃ low temperature, which result in the methods and theories achievments on the low temperature start ability of spark ignition heavy fuel DI aviation engines.as well as, the research on combustion knock formation and inhibition mechanism under the high temperature,heavy load condition will be studied in this project, including heavy fuel spray structure and injection rate impcat on mixture mixing rate, heavy fuel mixture activity inhibition by EGR, in-cylinder pressure and temperature distribution influence on heavy fuel combustion process, which exploring knock formation and control stratigies of heavy fuel piston-type DI aviation engiens under the high temperature and heavy load conditions. It has great acadamic significance that carrying out research and deeply understanding on combustion mechanism of heavy fuel piston-type DISI aviation engiens under the critical conditions, and important guidance on explore the implementation of heavy fuel DISI aviation engien efficient clean combustion as well.

本项目拟采用可视化、激光诊断、数值模拟和发动机台架试验相结合的方法，开展点燃式活塞航空重油直喷发动机临界工况条件下燃烧基础理论研究：开展低温（-20℃）环境下重油点燃和快速燃烧机理研究，系统研究低温环境下重油喷雾微结构及雾化机理、缸内压缩行程重油油雾再聚合对混合气混合率影响、混合气活性改善与点火能量对低温启动时缸内火核形成及火焰传播影响机理，为实现重油发动机低温起动能力提供方法和理论依据；开展高温大负荷工况下重油燃烧爆震产生和抑制机理研究，系统研究重油喷雾结构及喷油速率对混合气混合率影响、EGR对重油混合气活性抑制、缸内温度及压力分布对重油燃烧过程的影响规律，探索高温大负荷条件下重油发动机爆震机理及控制策略。本项目研究对深入理解点燃式活塞重油直喷发动机临界工况条件下燃烧机理、丰富和发展点燃式发动机燃烧理论具有重要理论意义，对探索点燃式重油活塞直喷发动机高效清洁燃烧技术途径具有重要指导价值。

本项目通过采用可视化、数值模拟和发动机台架试验相结合的方法，开展了点燃式活塞航空重油直喷发动机临界工况条件下燃烧基础理论的研究。围绕低温环境下重油点燃和快速燃烧机理研究方向，系统研究了低温环境下重油喷雾微结构及雾化机理、缸内压缩行程重油油雾再聚合对混合气混合率影响、混合气活性改善与点火能量对低温启动时缸内火核形成及火焰传播影响机理，为实现重油发动机低温起动能力提供方法和理论依据；围绕高温大负荷工况下重油燃烧爆震产生和抑制机理研究方向，系统研究了重油喷雾结构及喷油速率对混合气混合率影响、缸内温度及压力分布对重油燃烧过程的影响规律，基于时域和频域下探索高温大负荷条件下重油发动机爆震机理及控制策略。依托本项目核心基础理论研究成果，解决了重油航空直喷发动机的关键技术问题，研制成功了无人机用重油直喷航空发动机样机，正在进行工程应用转化。本项目研究成果对深入理解点燃式活塞重油直喷发动机临界工况条件下燃烧机理、丰富和发展点燃式发动机燃烧理论具有重要理论意义，对探索点燃式重油活塞直喷发动机高效清洁燃烧技术途径以及无人机重油直喷活塞航空发动机的工程研制与生产具有重要指导价值。为解决西方发达国家在无人机重油航空发动机领域对我国国防及安全领域的“卡脖子”工程核心技术问题奠定了扎实的理论基础，提供了有力的技术支撑。