结构参数对气动雾化喷嘴雾化特性影响研究

Influence of structural parameters on the atomization characteristics of air-assisted atomizer

为获得喷嘴结构参数对气动雾化喷嘴雾化特性的影响,通过实验测试与数值计算结合的方式对气动雾化喷嘴的雾化特性进行了研究。实验测试了不同燃油压差和雾化空气压力下喷嘴的SMD与喷雾锥角。数值计算采用VOF模型模拟了喷嘴内部的气液两相流动和喷嘴结构参数对雾化特性的影响。结果表明:燃油压差对雾化特性的影响不明显,在较低的燃油压差下雾化空气压力对雾化特性影响明显;在旋流室内由于中心负压的存在,会将空气吸入旋流室,形成具有强烈湍流的空气芯;不同结构参数对喷嘴雾化参数的影响不同,喷口直径d 1对流量系数的影响最大,喇叭口角度α对液膜厚度的影响最大,旋流片倾斜角β对喷雾锥角的影响最大。为达到满意的燃油雾化质量,应对喷嘴的结构参数进行优化。

In order to obtain the influence of the atomizer structure parameters on the atomization characteristics of the pneumatic atomizer,the atomization characteristics of the pneumatic atomizer were studied by the combination of experimental test and simulate calculation.The SMD and spray cone angle of the atomizer were tested under different fuel pressure and atomized air pressure.VOF model was used to simulate the effect of gas-liquid two-phase flow and atomizer structure parameters on atomization characteristics.The results show that the influence of different fuel pressure on atomization characteristics is not obvious,but the influence of atomization air pressure on atomization characteristics is obvious under low fuel pressure difference;because of the existence of center negative pressure in the swirl chamber,air is sucked into the swirl chamber to form air core with strong turbulence;different structural parameters on atomization parameters is different,and the influence of atomizer diameter D1 on flow coefficient.The angle of the horn angleαhas the greatest influence on the thickness of the liquid film,and the inclination angle of the swirling plateβhas the greatest influence on the spray cone angle.In order to achieve the satisfactory fuel atomization quality,the structural parameters of the atomizer should be optimized.