Theoretical Research Of Analysis On Characteristics And Influencing Factors Of Spray And Atomization Of Diesel Fuel

Currently, a variety of methods are taken to improve the efficiency of the diesel engine, and this problem is focused on and researched by diesel experts and scholars. To solve this problem, considering and studying the combustion efficiency of the diesel engine is paid more attention by most of scholars. As for improving the combustion efficiency of the diesel engine, this paper is achieved by studying the spray and atomization of the diesel engine. For a certain type of diesel engine, mathematical models are established, which are about the fuel that flows inside the nozzle and atomizes outside the nozzle. Meanwhile, CFD methods are used for numerical simulation. Finally, some results are got.For the injector nozzle of a certain type of direct injection diesel engine, its calculation model is established, which is based on the needle valve of the injector reaching the maximum lift. Based on the theory of diesel injection and computational fluid dynamics, the Fluent software and VOF model are used in this article to simulate the flow of the diesel fuel inside the nozzle which is under the different injection pressures, different orifice diameters and different back-pressure.Based on the simulation of nozzle spray of a certain type of direct injection diesel engine, the atomization of the diesel fuel which is in the combustion chamber of the diesel engine is researched in this paper. For the study of this phenomenon, a model of the combustion chamber is established in this paper. Combining with the basic equations of fluid flowing (mass conservation, energy conservation and momentum conservation), the k-ε turbulence equations and the atomization equations, the Fluent software and DPM model are used in this paper to simulate the variation regulation of penetration distance, SMD (Sauter Mean Diameter) and other parameters when the back-pressure of the combustion chamber, Injection pressure and nozzle diameter are different.After the simulation of the spray and atomization process of the diesel engine, the post-processing software is used to deal with the simulative results. At the end, various factors (nozzle diameter, injection pressure and back-pressure) which impact on the characteristics of the fuel spray and atomization are analyzed.