关键词: 均质压缩燃烧, 微发动机, 泄漏, 着火界限, 自由活塞, 变刚度, 机器人关节, 柔性关节

Abstract: The visual experiment of homogeneous charge compression ignition (HCCI) in micro combustion chamber is carried out, some qualitative analysis is got, and multidimensional simulation model based on this experiment is built. Based on the propane combustion kinetics, the numerical calculation method for combustion process coupling with the free-piston movement is put forward, through editing the dynamic mesh subroutine in STAR-CD, the process of HCCI in the micro chamber is studied. The influence of various characteristics on micro HCCI is researched, and the compression ignition range in an ideal model is got, when the dimensionless parameter of compression ratio is not less than 55, the mixture can always be compressed ignition. The influence of gas leakage on combustion process and the variation of compression ignition limit under different leakage size are also revealed, all this research can be the basic theories for designing the micro free piston engine .

Key words: Free-piston, Homogeneous charge compression ignition (HCCI), Ignition limit, Leakage, Micro engine, Flexible Joint, Robot Joint, Variable Stiffness