多毛细管静电雾化模式实验研究

Experimental study on electro-spraying modes from multi-capillary

采用高速数码摄像技术,通过图像对比与分析,获得了无水乙醇的一些多毛细管静电雾化模式,依据无量纲流量α和静电Bond数β对这些模式进行分类,结果表明:与单毛细管静电雾化模式相似,在多毛细管静电雾化模式出现了滴状、纺锤、射流及多股射流等雾化模式,并随着电压与流量的增加依次出现转变;同时由于毛细管、射流之间的库仑力作用,两股射流呈现对称向外倾斜分布.随着静电Bond数值的增大,两种多毛细管出现纺锤和脉动射流模式的重复频率增多,且两种模式的摆动幅度随之减小,当静电Bond数值增大到某一值时,纺锤模式将会转变为脉动射流模式;当静电Bond数值继续增大时,两种多毛细管均产生多股射流模式,且其射流数目随着静电Bond数值的增加而有所增多.

High speed digital camera was used to record eletrohydrodynamics spraying modes of multi-capillary with ethanol. The spraying modes of multi-capillary were obtained by analyzing the pictures,and the effect of operating parameters on electro-spraying modes was discussed. The spraying modes with two configurations were classified by the dimensionless parameter flow（ α） and electric Bond number（ β）. The experimental results indicated that similar to spraying mode of mono-capillary,dripping,spindle,jet and multi-jet modes could be observed in spraying mode of multi-capillary. The modes could transits from one mode to another with varying applied voltage and flow rate. The two jets from double-capillary showed symmetrical skewed distribution due to Coulomb repulsive forces between them. Although there are different configurations for two kinds of capillaries,the spindle and pulsated jet modes could be observed. For these two modes,the frequency of spindle and pulsated jet ejected from the capillary would also increased and the swing range of the spindle and jet would reduce with an increase in electric Bond number. The transition from spindle to pulsated jet mode would be observed at a critical electric Bond number. With electric Bond number further increased,the multi-jet mode would be observed for two configurations. The number of jet increased with an increase in electrical Bond number.