Abstract
In diesel engines the fuel injection system produces the spray, which directly affects the combustion of the fuel, which in turn determines the production of pollutants. In spite of this, the details of this causal relationship remain unclear. There is, however, a lack of quantitative experimental data for determining and visualizing the cavitation inside real size diesel injector nozzle. The present work is devoted to analyze analytically the flow pattern inside the nozzle of a diesel engine working with hydrocarbon fuel (Diesel fuel) and to predict the relationship between the various flow parameters and occurrence of fuel cavitation in such nozzles. Basic physical parameters affecting this phenomenon are identified and quantified while the effect of nozzle geometry, fuel injection pressure, and engine cylinder temperature upon the flow pattern and occurrence of cavitation in such nozzles are assessed. In this study, a commercial computational fluid dynamics (CFD) package (FLUENT-T grid) is used while a computational grid is generated for the real geometry of diesel injector nozzle using (ANSYS). The suitability of the generated computational grid to give reliable results is examined using the suitable procedures and techniques. The results indicated that, cavitation modeling has reached a stage of maturity and it can usefully identify many of the cavitation structures present in internal nozzle flows and their dependence on nozzle design and flow conditions. The qualitative distributions and comparison of cavitation inception and distribution as well as flow parameters at the nozzle exit are also studied.
Highlights
In order to understand the whole breakup process of the diesel spray, it is necessary to determine the phenomena which lead to primary and secondary breakup caused by interaction with the dense gas phase and collision with other liquid elements
The results from this study have demonstrated that the use of the multiple fuel injection strategy can effectively reduce the NOx emission from diesel engines
We report a computational investigation of the internal nozzle flow and cavitation characteristics in a real size diesel injector
Summary
In order to understand the whole breakup process of the diesel spray, it is necessary to determine the phenomena which lead to primary and secondary breakup caused by interaction with the dense gas phase and collision with other liquid elements. From the point of view of the internal flow, the nozzle outlet velocity increases when cavitation appears This phenomenon can be explained by the reduction in the cross section of the liquid phase in the outlet section of the nozzle hole. That makes the present study results unrevealing the properties of the internal flow patterns of a diesel injection nozzle and in particular the cavitation inside the injector nozzle with. The present numerical study aims at furthering of the cavitation processes that occurs inside diesel injector, especially under high-pressure injection conditions. We believe that in the parametric present study it is the first time to introduce the originality of cavitation phenomenon inside the real size diesel injector nozzle effectively under realistic injection pressures and nozzle geometry as well as the system temperature
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
