水平分布双气泡运动特性的可视化实验

Visualization study on dynamic behaviors of horizontal arranged bubbles

为了研究双孔喷气工况下,孔径及孔间距对气泡的影响规律,通过可视化实验方法研究双孔壁面逸出气泡的运动特性,对不同孔径及孔间距情况下的两列气泡的运动轨迹、气泡脱离尺寸、气泡速度进行分析,并与单孔气泡生成及运动特性进行对比,得到孔口间距及孔口直径对气泡的影响规律。实验结果表明,当两列气泡并排上升时,两气泡之间距离并不会保持恒定,而是会出现相互靠近远离再靠近的循环震荡过程,且孔间距越小,气泡上升时所伴随的左右震荡的振幅越大;在孔径及气体流量均相同时,孔间距越小,脱离尺寸越小,气泡最终的稳定速度越小;当孔间距及气体流量均相同时,孔径越大,气泡的脱离尺寸越大,脱离尺寸与单孔情况的差值越大,气泡最终的稳定速度越大。

In order to study the effects of orifice diameter and separation distance on bubbles generated by twin-orifice, the motion characteristics of bubbles from the twin-orifice were studied by a visual experimental method. Bubble detaching size, velocity and trajectory under different apertures and distances between orifices were analyzed and compared with those of single orifice conditions. The results show that two bubbles oscillate during rising, and the distance between the two bubbles do not remain constant during approach-apart-approach movements. Furthermore, the amplitude of the oscillation increases with the decrease of separation distance. The bubble detaching size becomes smaller with less separation distances and the final stable bubble velocity is lower when studied under same pore diameter and flow rate. When the pore spacing and gas flow rate are the same, the bubble detaching size is bigger with bigger pore diameter, and the difference of detaching sizes between the twin-orifice and the single orifice becomes larger. The final stable velocity of the bubble is larger as well.