Abstract
New approaches to modelling of some fluid dynamics, heat transfer and combustion processes in diesel engines are discussed. Simple analytical expressions for fuel spray penetration are derived in two limiting cases, the initial stage and the two phase flow regime, with and without taking into account the effects of turbulence. Newton's law of cooling is shown to underestimate the initial heat flux between fuel droplets and a gas. This problem is rectified by replacing the gas thermal conductivity hy the effective thermal conductivity. A new analytical solution of the heat conduction equation inside a spherical fuel droplet is suggested, assuming that the droplet is heated by convection from surrounding hot air - a situation typical in diesel engines. A new approximation for the average absorption coefficient of semi-transparent droplets is discussed. The Shell model is applied to modelling autoignition in diesel engines. A new mathematical formulation of this model is discussed.