直喷汽油机燃烧系统开发中的喷雾激光诊断技术

Laser diagnostics for spray of spark ignition direct injection (SIDI) combustion system

我国的直喷汽油发动机(SIDI)技术开发还不成熟。在SIDI燃烧系统的研发中,激光诊断、三维计算流体力学(3-DCFD)和基于光学发动机的燃烧诊断是三种重要技术。激光诊断技术可对燃油雾化与蒸发过程进行可视化以及定量测量,为数值计算和建模提供实验验证进而提高仿真的精确性,为缸内混合气形成过程及燃烧诊断提供直观的物理描述和解释。该文综述了SIDI喷雾的激光诊断技术,它涵盖了对喷雾结构、流场、粒径、燃油蒸发、混合气浓度场等的测量技术,为直喷燃烧系统中喷雾、气流运动和燃烧室形状三者的匹配与优化提供重要技术手段。

The technologies for development of spark ignition direct injection （SIDI） engines still need further research in China. Advanced spray laser diagnostics, three dimensional computational fluid dynamics （3-D CFD） modeling and the combustion diagnostics based on optical engine play leading roles in the development of SIDI combustion systems. Among these technologies, advanced laser diagnostics is becoming increasingly important, because through laser diagnostics one can realize visualization and quantitative measurements of in-cylinder processes which are essential for validation of CFD modeling and understanding the physical phenomena in the mixture formation and combustion processes. This paper summarizes and compares various technologies in spray laser diagnostics which are used to provide information for modern SIDI combustion system development. The review includes diagnostics for spray structures, tlow fields, droplet sizes and fuel evaporation, which enables optimization and matching of the spray, air flow and the combustion chamber of an SIDI combustion system.