On laser induced single bubble near a solid boundary: Contribution to the understanding of erosion phenomena

Abstract

Cavitation erosion is an especially destructive and complex phenomenon. In order to understand its basic mechanism, the dynamics of laser-induced vapor bubbles have been investigated. Special experimental devices have been used to record ultrafast visualizations and pressure measurements. From these measurements, the different sources of stresses, induced on the solid wall by the presence of the bubble (shock wave, microjet), have been characterized. The “water hammer” pressure associated with the microjet velocity varies up to 210 MPa. When the bubble collapses near a solid wall, the pressure emitted is less than in an infinite medium. Pressure values up to 2.5 MPa have been found. These values have been associated with the duration of the pressure applied to the solid wall, which is about 30 ns for the microjet and more than 300 ns for the shock wave. These results have been correlated with the analysis of damage created on the surface sample.

Dynamics of laser-induced bubble pairs

“…The physical action of liquid jets is frequently discussed with respect to surface damage and erosion (Benjamin & Ellis 1966;Tomita & Shima 1986;Isselin, Alloncle & Autric 1998;Philipp & Lauterborn 1998), but a beneficial effect of jetting can also be reached if sufficient control over the effect is established. In particular, directed fluid transport over short distances or micro-manipulation of adjacent objects are attractive perspectives.…”

Study of the application of Acoustic Emission technology for on-line monitoring of bubble phenomena and flow patterns in two-phase gas-liquid flow

“…High pressures arise from the bubble activities (formation and collapse) which cause compression to liquid and become an important factor in the motion near the end of collapse when eventually the pressure pulse radiated from the bubble collapse centre will take the form of a shockwave [28]. Shockwave then propagates with a direct function of the pressure at any given point: the higher the pressure, the greater the velocity of sound [29]. This shock wave propagation can be detected by underwater sensor pressures such as hydrophone, microphones and AE transducers.…”

Numerical and Experimental Study of the Interaction of a Spark-Generated Bubble and a Vertical Wall

“…Spark generators have been used for studying bubbles in a liquid for quite a long time [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. DYNAFLOW, INC. has several test chambers that can be used to simulate full-scale bubble dynamics, and is equipped with flow diagnostics tools including high speed photography and pressure measurement capabilities.…”

“…In such cases the bubble collapses asymmetrically, resulting in the development of a reentrant jet followed by a toroidal bubble formation [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. This high speed reentering jets can be very damaging.…”