Abstract: Radiation heat transfer is extremely important for diesel engine and occupies very high ratio in total heat transfer capacity of in-cylinder. It is directly related to the diesel engine heat efficiency and all kinds of heat load and heat intensity caused by heat transfer. At the same time, the study on radiation heat transfer on combustion system is also important, for the combustion performance of internal combustion engine and formation of all combustion products will be observably effected. Hence, the multi-dimensional transient numerical simulation of in-cylinder radiation heat transfer is performed by using discrete transfer radiation method (DTRM), and the effect of surface emissivity and fuel injection advance angle on in-cylinder radiation heat transfer is investigated. The results show that the maximal radiative heat flux of piston surface is larger than that of head surface; the maximal radiative heat flux of head surface is not at the central position but changes with time. The radiative heat flux of wall surfaces is enhanced with the increase of emissivity of wall surfaces; the radiative heat flux of all combustion chamber components is directly affected by the advance angle of fuel injection.

Key words: Diesel engine, In-cylinder, Multi-dimensional numerical simulation, Radiation heat transfer