Study of the interaction of the flow field and the fuel jet in particulate formation as related to diesel engines: Sixth quarterly progress report, October 15, 1988--January 15, 1989

摘要

Information available in the literature indicates that the particulate emissions from diesel engines can be reduced by controlling the fuel injection process or the air motion within the combustion chamber. Within the constraints of the current engine designs, the above approach generally results in increased NO/NO(sub x) emissions due to improvements in the combustion event. While the kinetic mechanism for NO/NO(sub x) emissions is well defined in terms of the extended Zeldovich mechanism, the complex nature of the diesel combustion process makes it impossible to predict the integrated effects of variations in the physical processes on the total NO/NO(sub x) emissions. While it is felt that both the particulate and the NO/NO(sub x) emissions can be controlled in the engine, the effects of variations in the physical processes must be defined for both the particulate and the NO/NO(sub x) emissions. The objective of this project is to develop a data base which defines the interactions of the injection, atomization, and mixing processes as well as the thermodynamic state and fuel composition on the particulate and the NO/NO(sub x) emissions. The experiments are being performed using standard diesel fuel injection equipment injecting into a flow-tube reactor, where the flow field and thermodynamic state are controlled and well defined. The particulate and NO/NO(sub x) emissions will be measured at point locations within the reactor, using a quenching probe in conjunction with a dilution tunnel as defined by the EPA specifications. The work plan for this project involves four general tasks or phases. These include: Task 1. Flow Modeling and Flow-Tube Reactor Preparation; Task 2. Flow Measurement and Spray Analysis; Task 3. Combustion Experiments; Task 4. Data Analysis; Accomplishments in each task are described.