CFD Simulation On Two-Phase Flowing Of Internal Airblast Diesel Atomizer

In fact, the process of fuel breakup and atomization is a kind of instability phenomenon of the liquid jet. In order to increase the oil surface area and promote efficient combustion, the instability process of the jet is always used to make the fuel atomization in engineering. So study on the mechanisms of breakup and atomization of liquid is not only important on theory, but also owns the engineering background.Being used to analyze the flow, mixing and mass transfer characters of fluid, Computational Fluid Dynamics (CFD) can not only save a lot of resource, but also get some important local data that cannot be gathered in experiment. Now CFD technology is regarded more and more in the fields of the design and optimization. The article mainly uses the professional software-CFX and adopts the viscosity models, i.e. RNG k-εmodel, which can be suitable, with moderate cost, to simulate the atomizing characteristics.The injection and atomization process is dynamic, which is not only affected by the nozzle configuration and injection pressure, but also affected by the temperature, pressure, gas flow. This thesis conducts a theoretic and numerical investigation on the mechanisms of the breakup and atomization of viscous liquid jets, and the results obtained from this studying are applied in the process simulation in internal mix sprayer. The following terms have been finished: the detailed review of the previous works on the stability analysis of liquid jets and it's breakup and atomization are given, in addition, the fuel atomization models are introduced in this dissertation, introduce the development, characters and working steps of CFD, analyze turbulence characteristics, educe the intention and the signification of the article; generalize the knowledge about CFD,establish the geometry model and choose the mathematics model,ensure appropriate physics model, put up appropriate physical model,simulate the process of the atomization of the diesel oil , gain the good simulation results, such as distributing of the velocity field, pressure field and diesel oil density concentration field. Then the study about the spray characteristics of internal mixing atomizer is obtained. Many factors such as air-liquid angle, outlet diameter geometrical size, air-liquid rate, oil velocity, air velocity, pressure operating condition and liquid...