Numerical Simulation Of Homogeneous Charge Compression Ignition (HCCI) For Vehicle Diesel Engine

This paper study in homogeneous charge compression ignition(HCCI) vehicle diesel engine with numerical simulation. HCCI can greatly reduce engine emissions of soot particles and nitrogen oxides (NO_X), it's regarded as the potential solution of current problems of the internal combustion engine emissions in future, and has become the research focus in Internal Combustion Engine in and out of our country. Unlike conventional diesel engine and gasoline engine, the heat release of homogeneous charge compression combustion almost entirely happens in the process of spontaneous combustion of the mixed gas, the combustion in HCCI engine is controlled by its chemical kinetics only, different from the traditional combustion process which is directly controlled by turbulent combustion flame propagation or fuel air mixing process, there's no obvious flame propagation in HCCI combustion, with the advantages of lower and uniform maximum combustion temperature within the cylinder, less PM and NO_X, and high thermal efficiency because of its combustion closes to the equivalent volume combustion.Because of the advantages of high efficiency and low emissions, homogeneous charge compression ignition has attractive prospects in the application of the internal combustion engine, but there're still many problems have to be solved, how to achieve the effective control of the combustion starting point and combustion process is the key. Against diesel engine with homogeneous charge compression ignition, this paper study on premixed combustion ignition and combustion law with numerical simulation method. Through the establishment of pre-mixed gas ignition and combustion model, study on the factors that impact the pre-mixed combustion ignition moment such as inlet temperature, excess air ratio, compression ratio and the injection timing, to get the premixed combustion process mechanism of low-pollution vehicle with diesel engine, and reveal the gas mixture formation and ignition control rules of this combustion. At the same time, this paper analyzed some problems in the course of HCCI numerical simulation and the way to control diesel HCCI combustion process comprehensively, and explored the current proposed techniques, to study diesel HCCI combustion better.Through this study, learned more about the factors that impact on the combustion starting point and combustion process of diesel engine with homogeneous charge compression combustion, as well as the role, the extent and the integrated control of the combustion process of these factors, to research the method which could control diesel HCCI combustion effectively, the results of this paper is of important guiding significance and practical value to the further tests and development of practical HCCI diesel engine in future.