HYDRODYNAMIC PROCESSES IN DYNAMIC BUBBLE PRESSURE EXPERIMENTS .1. A GENERAL-ANALYSIS

The transition of the bubble lifetime in maximum bubble pressure exper iments to milliseconds and submilliseconds can be arranged by decreasi ng the capillary length. In this time range, a transitional hydrodynam ic regime results with spatial inhomogeneities of the gas flow. As a c onsequence, a considerable increase of the calculated deadtime of a gr owing bubble can be expected as compared to the Poiseuille regime. An equation has been derived and discussed qualitatively for estimating t he bubble lifetime and a correction Delta t(d) to the deadtime. The gi ven approach neglects the variation of surface tension during the bubb le growth, and the growth of the bubble is assumed to be purely hydrod ynamic. Also, surfactant adsorption accompanied by a decrease in capil lary pressure was not considered in the present approach.