Development of a zero-dimensional Diesel combustion model.: Part 1:: Analysis of the quasi-steady diffusion combustion phase

The aim of this work is to identify and quantify the influence of injection parameters and running conditions on Diesel combustion. This theoretical-experimental analysis is the basis for the development of a zero-dimensional Diesel combustion model. The objective of this first part is to analyze the physical variables and processes that control the central phase of the quasi-steady Diesel diffusion combustion. For that purpose, a parameter as the apparent combustion time (ACT) characteristic of a diffusion combustion process has been used. This parameter allows to obtain explicit relations between, on the one hand, the injection rate law and in-cylinder conditions (air density, oxygen concentration...), and on the other hand, the rate of heat release. Results show a good correlation between the ACT. and the instantaneous values of in-cylinder gas density, injection velocity, oxygen concentration and the nozzle diameter. (C) 2003 Elsevier Science Ltd. All rights reserved.