Analysis Of Combustion And Particulate Emissions For Marine Diesel Engine Based On CFD

Injector needle coupling is the final implementation of diesel fuel injection system components,the decomposition of jet fuel atomization quality plays a most crucial role,and ultimately directly reflected in the power performance of diesel engines,economic indicators and the index of harmful engine exhaust.Atomization of fuel in the cylinder directly affects the emissions of primary particulate matter of the soot particles of the engine,and also has a great impact on the secondary particles such as NOx.Study and analysis of the impact of fuel in the cylinder of the influencing factors of great significance.In this paper,CFD three-dimensional fluid simulation software was used to simulate and analyze the flow of fuel in the jet hole of the diesel engine and the jet and atomization of the jet outside the jet hole.Some experience was gained.Through reviewing the literature results,it is clear that the turbulence of turbulence in the combustion chamber,turbulent internal turbulence and the cavitation of fuel in the orifice of the needle valve coupler are the three main factors that break up the atomization of the jet of fuel jet.And more and more The research thinks that the relationship between the Cavitation of fuel in the injection hole occupies an important position.In this paper,along with this new idea,we choose three injector with different nozzle parameters,and create and cut the fluid solid model in the injector.Mesh module of ANSYS Workbench is used to mesh the model.Inflation mesh method is used to deal with the boundary layer.Two-phase flow model and hole model are added.The initial conditions are imposed on the model by applying constraints and loads.The three models of fuel injectors are put under pressure,Turbulent kinetic energy,gas phase density,velocity and velocity vector.The cloud distribution charts of each field were used to describe the flow pattern of the fuel,and the interpretation and comparison of the cloud images were made.The AVL Fire software is used to establish a three-dimensional model of L250 diesel engine combustion calculation.The fan-shaped area that represents the whole cylinder combustion process is selected.Turbulent flow,spray,spontaneous combustion and combustion are set and the parameters in the model are determined.The calculated values are in good agreement with the measured values,indicating that the three-dimensional calculation model constructed basically reflects the actual combustion process in the cylinder.Different nozzle injection programs were carried out to analyze the concentration and temperature fields related to particulates in the combustion process.Through the diesel engine test,the programs were analyzed and evaluated.