ANALYSIS OF INSTABILITY OF A CYLINDRICAL SOAP FILM OF FINITE DIMENSIONS

By means of experiments of instability of a uniform cylindrical soap f ilm, Boys had showed that the bubble molded by the film is unstable wh en its length is greater than its circumference. Recently that is gene rally called the Rayleigh Criterion. In this paper, a linear theory in hydrodynamics is applied to analyze the stability of the cylindrical soap film supported by two equal size disks; all conditions of the sta tionary wave on the end plates of two disks are given. From here we ge t that the Rayleigh Criterion on the stability of the cylindrical soap film is proved.