ABSTRACT
The problem of the inception of cavitation is formulated in terms of a comparison of the breaking strength or cavitation threshold at each point of a liquid sample with the principal stresses there. A criterion of maximum tension is proposed which unifies the theory of cavitation, the theory of maximum tensile strength of liquid filaments and the theory of fracture of amorphous solids. It is argued that the liquid ruptures in tension at nucleation sites; the cavity then fills with gas and the liquid flows. Liquids at atmospheric pressure which cannot withstand tension will cavitate when and where tensile stresses due to motion exceed one atmosphere. A cavity will open in the direction of the maximum tensile stress which is 45 ffi from the plane of shearing in pure shear of a Newtonian fluid. An analysis of capillary collapse based on viscous potential flow leads to the total collapse of a capillary filament in a finite time; before this the filament enters into tension and presumably would break under tension. For water the critical radius is about 1.5 microns.
