Some Compressibility Effects in Cavitation Bubble Dynamics

Author: Schneider, Arthur John Rudolph

Year: 1949

Degree: Dissertation (Ph.D.)

Advisor: Hollander, Aladar

Committee Member: Unknown, Unknown

Option: Mechanical Engineering; Physics

DOI: 10.7907/C2VH-HM56

Abstract

  1. Theories on the dynamics of cavitation are critically examined, and are found to need clarification.
  2. The contents of a bubble formed from a submicroscopic nucleus are agreed to be almost entirely water vapor. This water vapor is shown to be unable to offer decisive resistance to inward flow during the finite portion of the collapse.
  3. The effect of compressibility of the liquid is analyzed in detail. It is found to reduce velocities noticeably, but does not, in itself, eliminate the anomaly of an infinite collapse velocity as the bubble radius approaches zero. The pressures in the fluid surrounding the bubble are found to be markedly reduced by the assumption of compressibility.
  4. Energy is found to be continually transported inward during the collapse period.
  5. The mechanism of rebound of a compressible liquid is examined when the bubble collapse is arrested by an immovable barrier of finite radius. A shock wave is formed followed by a tension wave responsible for rupturing the liquid.
  6. The shock wave is estimated to carry off 47% of available energy, and limit rebound to 81% of former size.
  7. The maximum pressure in the outgoing shock wave is found to be incapable of damaging a metallic wall when the point of collapse is not on that boundary.

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