Abstract:In order to obtain ignition and combustion characteristic parameters of the micro Homogeneous Charge Compress Ignite(HCCI) free-piston engine,numerical model of operation process of micro HCCI free-piston engine was developed.A method was proposed to simulate the operation of single-shot micro HCCI free-piston engine based on the kinetic characteristics of free-piston engine.A method of varying the influencing parameters was used to simulate the operation of single shot process of micro HCCI free-pistonengine coupled with the detailed chemical kinetic model of propane.The change of ignition time and combustion characteristics were obtained under the conditions of different initial conditions.The computational results indicate that initial temperature,initial pressure and equivalence ratio of fuel have important influence on ignition and combustion process of micro HCCI free-piston engine.