CAVITATION AND THE STATE OF STRESS IN A FLOWING LIQUID

The problem of the inception of cavitation is formulated in terms of a comparison of the breaking strength or cavitation threshold at each p oint in 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 t heory of fracture of amorphous solids. Liquids at atmospheric pressure which cannot withstand tension will cavitate when and where tensile s tresses due to motion exceed one atmosphere. A cavity will open in the direction of the maximum tensile stress which is 45 degrees from the plane of shearing in pure shear of a Newtonian fluid. Experiments whic h support these ideas are discussed and some new experiments are propo sed.