Efflux Time of Soap Bubbles and Liquid Spheres

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Science  02 Jun 1967:
Vol. 156, Issue 3779, pp. 1220-1222
DOI: 10.1126/science.156.3779.1220


The efflux time, T, of gas from soap bubbles of radius, R, through their blow tube of length, 1, and radius, p, is given by the equation

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where η is the viscosity of the gas and ό the surface tension of the bubble solution, all in centimeter-gram-second units. Similar relations between time and diameter were established for the flow from one bubble to another or from one bubble within another. The same relations hold for the flow of liquid spheres, suspended in another liquid of equal density, following Plateau's classic method. They have been extended to the flow of spheres to cylinders and catenoids of rotation. In all these cases the driving force is the surface or interfacial tension, creating an excess pressure as defined by Laplace's equation.