【摘要】 采用LPI-3衍射式激光粒子测径仪与LE-3雾化角测量仪对船用旋流蒸汽机械雾化喷油器进行了试验研究,得到了雾化油滴索特平均直径及喷油量与压力的变化关系;利用Realizable k-ε模型模拟气体湍流流动,随机轨道模型模拟液滴运动;并用LISA模型和TAB模型模拟液滴变形和破碎,对旋流蒸汽机械雾化喷油器的雾化过程进行了数值模拟,分析了喷油器内雾化空气和油质量流量对雾化特性的影响,模拟的结果与试验结果吻合得较好。研究表明,在喷油压力高于1.1MPa时,喷油器特性符合机械雾化喷嘴的一般规律,但当喷油压力较低时,雾化规律相反,喷油压力越低,雾化粒度越细。由此表明,旋流蒸汽机械雾化喷油器可以极大地改善低工况雾化质量,具有较大的调节比,气耗量也优于常见的气动雾化喷油器。更多还原

【Abstract】 By using a LPI-3 diffraction type caliper gage of laser particles and a LE-3 atomizing-angle measuring device an experimental study has been conducted of the above-mentioned oil sprayer for marine use. Identified was the variation relationship between the Sauter mean diameter of atomized oil droplets and sprayed oil quantity on the one hand and its oil pressure on the other. By utilizing the Realizable k-ε model, the turbulent gas flow was simulated followed by a simulation of the droplet movement by using a random orbit model. The deformation and fragmentation of droplets were also simulated by employing the LISA and TAB models. A numerical simulation was performed of the atomization process of the above-mentioned oil sprayer along with an analysis of the effect of the atomized air and oil mass flow rate in the oil sprayer on the atomization characteristics. The simulation results are in comparatively good agreement with the test ones. The research indicates that when the oil spray pressure is above 1.1 MPa, the oil sprayer characteristics comply with the general law of mechanical atomizing nozzles. But when the oil spray pressure is relatively low, the atomization mechanism will take a reverse course, i.e. the lower the oil spray pressure, the finer the atomized particles. From the foregoing it can be shown that the swirling steam-based mechanical atomized-oil sprayer can maximally improve the atomization quality under a low-load operating condition and has a relatively large turndown ratio with a steam consumption rate lower than that of an often-used pneumatic atomized-oil sprayer.更多还原