'University of Babylon - Department of Mechanical Engineering, Faculty of Engineering'
Abstract
Includes bibliographical references (leaves 78-81).Reducing the pollution of new vehicles has become a priority to vehicle manufacturers, particularly given the fact that emissions requirements that must be achieved by diesel vehicles are becoming more stringent. Modem fuel injectors on common-rail diesel vehicles use very high rail pressures to aid atomisation and increase combustion efficiency. However, associated with the high injections pressures is the issue of nozzle cavitation. Cavitation leads to pockets of diesel vapour forming in the nozzle and it is hypothesised that this causes the formation of deposits in the nozzle. It is also suggested that the collapse of the cavitation vapour space results in extremely high temperatures within the nozzle, resulting in thermal cracking of the fuel and eventually the formation of carbon deposits. A two-dimensional axisymmetric CFD model with dimensions representative of an injector nozzle was constructed using a fully structured grid
