抄録
During the conventional Diesel combustion soot and nitrogen oxide are formed due to the inhomogeneous mixture process. In homogeneous or partly homogeneous operation combustion occurs in premixed and lean conditions. Therefore soot and NOx emissions are significantly reduced. In the past the last-named operating modes have been investigated mostly by experimental test-bench measurements. So far, the nonexistence of easy to use and accurate combustion models for these types of combustion regimes have prevented researchers and developers from using one-dimensional simulation tools. Therefore a phenomenological combustion model for homogeneous and partly homogeneous Diesel combustion has been developed. The low temperature combustion and the ignition delays for high temperature combustion are calculated with a global reaction model. The high temperature combustion is modeled with a phenomenological approach which uses several fuel balance pools to represent different degrees of homogenization during partly homogeneous operating modes. A combined k-ε and density-difference approach is used to model the mixture formation during DI-modes. The developed model showed very good agreement with experimental results for homogeneous and partly homogeneous Diesel combustion with one set of parameters combined with very low computational time.
