Stimulation Researching Of Combustion Process Of Micro HCCI Free-Piston Engine

The structure of free-Piston Engine is simple, which is better suited to the development for micro.The method combinated HCCI with micro free-piston engine can not only avoid flame-quenching near the combustion chamber wall, but also solve the problem of ignition control of HCCI at the same time.Moreover, the efficiency of the energry of micro free-piston engine conversing to power is high. Therefore, the research based on HCCI combustion micro-free piston engine is expected to exceed restrictions by the smaller Combustor, and impact on the development of Power-Micro Electro Mechanical greatly.For the work characteristics of the micro HCCI free-piston engine, the two-dimensional models of the engine combustion under ideal conditions (adiabatic, no leakage), and considering the influnence of leakage and heat transfer respectively are established. According to relationship between the pressure on the piston and its velocity, the moving mesh procedures for simulating the piston work process are established to achieve the coupling gas chemical kinetics with the kinematics of piston. In this paper, the auther make use of the means of the chemical reaction coupled with the flow computing to model the whole working process of the HCCI free-piston engine single shot, using the software of STAR/Kinetics. The paper used the method of varying the influencing parameters to obtain the change of igniting time and combustion characteristic under the conditions of different stroke, different initial equivalence ratio, different compression ratio (initial piston velocities), further more, the paper provided the theory for controlling the combustion process. The influence of heat transfer and Leakage for the micro HCCI free-piston engine single shot process is researched respectively by the model contained the leakage or heat transfer, and got the conclusions that heat transfer impact on the entire operation process relatively small,and the influence of leakage is relatively larger.Finally, the paper studies the combustion characteristic in the micro HCCI free-piston engine operation process and the micro-engine dynamic performance, providing the theory for developmenting the micro-Power device.