The Dynamics of Cavitation Bubbles

TLDR

Liquid flow over a body can be noncavitating, cavitating with few bubbles, or cavitating with a single large cavity, and for the intermediate regime the pressure coefficient is assumed unchanged from noncavitating flow while nuclei influence bubble formation. The authors derive an equation of motion for vapor‑filled bubble growth and collapse and apply it to experimental observations. The derived equation is limited by finite evaporation/condensation rates and vapor/liquid compressibility.

Abstract

Abstract Three regimes of liquid flow over a body are defined, namely: (a) noncavitating flow; (b) cavitating flow with a relatively small number of cavitation bubbles in the field of flow; and (c) cavitating flow with a single large cavity about the body. The assumption is made that, for the second regime of flow, the pressure coefficient in the flow field is no different from that in the noncavitating flow. On this basis, the equation of motion for the growth and collapse of a cavitation bubble containing vapor is derived and applied to experimental observations on such bubbles. The limitations of this equation of motion are pointed out, and include the effect of the finite rate of evaporation and condensation, and compressibility of vapor and liquid. A brief discussion of the role of “nuclei” in the liquid in the rate of formation of cavitation bubbles is also given.