Numerical Simulation And Analysis On Influencing Factors Of Spray Characteristics Of Diesel Based On FLUENT

At present, scholars and experts working on the diesel engine promoted a number of experiments concentrating on how to improve the efficiency of diesel engine. Spraying and atomizing characteristics of the fuel will affect the mixture formatting and combusting process of diesel engine, which will affect the efficiency of the diesel engine and so on. Therefore, it is important to improve the fuel spraying characteristics for increasing the working efficiency of the diesel engine. While, Nozzle is a final execution parts in the diesel engine fuel injection system, which determines the atomization quality of fuel, then ultimately affects the performance of the diesel, such as fuel economy and vehicle emissions. Therefore, it is the trend of the time to have further study and analysis on the factors that influences the diesel engine fuel injection spraying. The paper mainly discusses two stages, which covers the fuel flowing inside of the nozzle and spraying outside of the nozzle.First, this paper uses ICEM CFD software to establish the geometric models of the nozzle and the fuel spraying field, then complete meshing for them. Combining with the diesel engine fuel injection spray theory and fluid mechanics basic equation, thi s paper establishes mathematical models of the nozzle and the fuel spray field. What’s more, this paper simulates the fuel flowing in the inside of the nozzle and fuel atomizing outside the spray nozzle hole respectively to the different nozzle number, different nozzle hole diameter, different injection pressure.On the basis of numerical simulation, this paper processes the results of fuel spray atomizing simulation and analysis of the number of nozzle hole number, the hole diameter, and the fuel injection pressure’s effects on the characteristics of fuel spraying. The results show that the nozzle hole number, hole diameter and the fuel injection pressure will have a greater impact on the fuel’s velocity when it flows out of the jet nozzle. After the fuel atomizes, nozzle’s atomization effects are obviously different under different conditions, mainly in aspects of penetration, spray cone angle and fuel droplet SMD.