Numerical Simulation Of Combustion Process And Emission Prediction For TBD234 Diesel Engine

Due to the relatively high thermal efficiency and operation reliability, Diesel Engines will still be the main engine of ship in the near future.Considering the deteriorating environmental problem caused by the emissions from ships, people pay more and more attention to the pollution problems of marine diesel engines. The core of emission reduction is to reduce the NOx and particulate content, and to improve the diesel engine combustion to meet the strict emission regulations is the most essential method. The diesel engine combustion is a physical and chemic process which is complex and changeable. The research method used in this thesis is software simulation with FIRE which is developed by the Austrian AVL company. Without the experiment restriction, this software can simulate the combustion in the combustion chamber and get the particular information which is difficult to measure.In this thesis, the compression stroke, combustion stroke and expansion stroke of TBD234 diesel have been simulated. The parameters in the model are adjusted to ensure the indicated diagram resulting from the simulation accorded with the experiment data. The factors impacting combustion as nozzle diameter, the injection timing, EGR and the intake temperature are studied in this thesis. Finally, the software is also used to study the spray and combustion progress in diesel engine with different combustion chambers. The in-cylinder flow field, fuel concentration field, temperature field are compared, and the mixtures of fuel and air in different combustion chambers are analyzed and contrasted, which can provide direction to design of combustion chamber.