Effect of radiation on diesel engine combustion and heat transfer

Abstract

An investigation of the effect of radiation on NOx emission was conducted for low temperature diesel engine combustion by using advanced numerical models in a Computational Fluid Dynamics code. The Discrete Ordinates Method (DOM) model was used for the prediction of radiation, which is mainly radiated from soot emissions. The advanced numerical model was able to predict the pressure and heat release rate for a wide range of Start Of Injection (SOI) timing cases. It was found that the influence of the radiation was larger on soot formation than on NOx formation. However, the influence of the radiation on the emissions was smaller than the influence of the wall temperature on emissions. The reaction-induced interaction between NOx and soot emissions was found to be very small, only up to 2.5% difference of engine-out NOx concentration.