A Photographic Study of the Dynamics and Damage Capabilities of Bubbles Collapsing Near Solid Boundaries

Abstract

The effect of proximal rigid boundaries on the motion and damage capabilities of spark bubbles is investigated by means of a qualitative photographic study. It is determined that an axially symmetric bubble collapsing nonhemispherically against a solid boundary can form a liquid jet which impinges against the solid boundary, but the jet has little or no damage capability. Observations of the toroidal minimum volume and associated damage to the boundary in the form of circular dents on indium indicate a pressure pulse damage mechanism.

Effect of hydrodynamic pressures near solid surfaces in the incubation stage of cavitation erosion

“…It is commonly agreed that the microjet and shock wave caused by a collapsing bubble in water are the main reasons for the cavitation erosion on solid surfaces. This statement is supported by experiment photographs as well as by theoretical analyses [2][3][4], which are enumerated by Hammitt [5] in a short review. The surface roughness is usually considered to take effect on cavitation erosion by affecting the cavitation inception [6], and an empirical relationship between the surface roughness and the incipient cavitation number was established by Arndt and Ippen [7].…”

Damages on steel surface at the incubation stage of the vibration cavitation erosion in water

“…Studies on the cavitation damage have accumulated since the pioneering work of Rayleigh [1] in 1917. It is known from the numerical simulations [2,3] and experimental results [4,5] that a high speed jet is generated when a bubble collapses near a solid wall, which is considered to be the main reason for the cavitation erosion on a solid surface. This statement is later supported by experimental photographs as well as theoretical analyses, which are enumerated by Hammitt [6] in a short review.…”

Study on effect of microparticle’s size on cavitation erosion in solid-liquid system

“…1 This statement is supported by experimental photographs as well as theoretical analyses, [2][3][4][5] which are enumerated by Hammitt 6 in a short review. On the other hand, the number of bubbles in the liquid may increase through heterogeneous nucleation according to the theory of Harvey et al 7 and recent experimental result.…”