Combustion Characteristics of Two Types of Porous Medium Engine Fueled with Liquid Fuel

As a new combustion concept,homogeneous and stable combustion can be realized in porous medium(PM) engine equipped with a chemically inert porous medium.Toward a further understanding of the properties of PM engine,the working processes of two types of PM engine fueled with liquid fuel were simulated by using the improved CFD software KIVA-3V.The effects of initial PM temperature and PM structure characteristics on compression ignition of the two types of PM engine were also discussed.Computational results show that both initial PM temperature and PM structure have impacts on the performance of the two types of PM engine.The initial PM temperature is a critical factor in determining the start of compression ignition in both types at a given compression ratio.Compared with the permanent contact type,compression combustion can be realized in the period contact type of PM engine at a lower initial PM temperature.The change of PM structure characteristics can directly affect the convective heat transfer between gas and solid phases,and the dispersion effects of the PM,as a result,have impacts on the occurrence of compression ignition of the two types of PM engine.