Development And Numerical Simulation Research On The New Mixture Formation Technology Of HCCI Diesel Engine

The internal-combustion engines had been employed widely in many fields since they birthed above 100 years ago. As the oil crisis and environment problem had been more and more serious, the conventional engines are not satisfied in economic behavior and environmental indices. The homogeneous charge compression ignition (HCCI) technology had obtained more regards because of its higher efficiency and ultra-low NO_x and particulate matter (PM) emissions at part load, and has been the research hotpoint.This paper researched the formation process of HCCI mixture using professional CFD software-FLUENT, based on the multiple type intake pipe injection technology.Firstly, this paper introduced the characteristics, development and status in quo of HCCI technology,the measures taken to counter the restricts of HCCI technology and three approaches to realize HCCI combustion in engines.Secondly, aiming at the new technology of admixture formation,this paper established the geometry model and chose the mathematics model and physics model and then set the parameters of simulation calculation.Thirdly, this paper simulated the formation process of HCCI admixture and gained simulation results. Through changing the parameters of diesel spray and the speed of engine, analyzed the influence of different parameters to the diesel spray and the mixture formation.At last, the conclusion was that the integrated intake pipe injection technology could form uniformity concentration admixture in a certain extent and the evaporation speed of diesel oil was influenced by the parameters of diesel spray and the speed of engine. As the spray pressure or temperature of vent-pipe increased,or diameter of nozzle reduced, the evaporation speed of diesel oil would enhance.And the angle of spray also influenced the evaporation speed of diesel oil.While the speed of engine increased,the evaporation speed of diesel oil would drop.This paper provided valuable reference for the researches of HCCI mixture formation and HCCI combustion employing in vehicles.