Keim Nathan C, Møller Peder, Zhang Wendy W, Nagel Sidney R
James Franck Institute, University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2006 Oct 6;97(14):144503. doi: 10.1103/PhysRevLett.97.144503. Epub 2006 Oct 3.
Using high-speed video, we have studied air bubbles detaching from an underwater nozzle. As a bubble distorts, it forms a thin neck which develops a singular shape as it pinches off. As in other singularities, the minimum neck radius scales with the time until the breakup. However, because the air-water interfacial tension does not drive the breakup, even small initial cylindrical asymmetries are preserved throughout the collapse. This novel, nonuniversal singularity retains a memory of the nozzle shape, size, and tilt angle. In the last stages, the air appears to tear instead of pinch.
我们使用高速摄像机研究了从水下喷嘴脱离的气泡。当气泡变形时,会形成一个细颈,在其 pinch off(此处可能是“ pinch off”,意为“捏断”,但不确定语境下是否准确,可根据实际情况调整)时会呈现出奇异的形状。与其他奇点情况一样,最小颈半径随时间变化直至破裂。然而,由于气 - 水界面张力并非导致破裂的原因,即使是很小的初始圆柱不对称性在整个坍塌过程中也会保留下来。这种新颖的、非通用的奇点保留了喷嘴形状、尺寸和倾斜角度的记忆。在最后阶段,空气似乎是撕裂而不是 pinch off。