Influence of Bubble Kinetic Energy on its Bouncing During Collisions with Various Interfaces

Abstract

the canadian Journal of chemical engineering 669Collisions and bouncing of the bubbles with water/gas and water/solid interfaces occurring within a time scale of milliseconds were studied. It was shown that the bubble kinetic energy at the moment of collision has a profound influence on the bubble bouncing prior to the bubble rupture at the liquid/gas interface and attachment to the hydrophobic or remaining arrested beneath hydrophilic solid plates. The mechanism of the bubble bouncing was analyzed and degrees of exchange of the kinetic energy into the bubble surface energy were determined. It was found that in the case of solids the degree of the energy conversion was lower for the hydrophobic solid-most probably due to the presence of air.On a étudié les collisions et les rebonds des bulles avec les interfaces eau/gaz et eau/solide qui surviennent dans des échelles de temps de la milliseconde. On montre que l'énergie cinétique des bulles au moment de la collision a une profonde influence sur le rebondissement des bulles avant la rupture des bulles à l'interface liquide/gaz, sur l'attachement à la plaque solide hydrophobe ou en dessous de la plaque solide hydrophile. On a analysé le mécanisme de rebond des bulles et déterminé les niveaux d'échange de l'énergie cinétique dans l'énergie de surface des bulles. On a trouvé que dans le cas des solides, le degré de conversion d'énergie était inférieur pour le solide hydrophobe, très probablement à cause de la présence d'air.

An investigation into the mechanism of the three-phase contact formation at fluorite surface by colliding bubble

“…As described elsewhere (Krzan et al, 2004;Malysa et al, 2005;Zawala et al, 2007) at this distance the detached bubble is at the initial (acceleration) stage of the motion and distribution of the adsorption coverage over the bubble surface can be still treated as almost uniform (Jachimska et al, 1998;Krasowska et al, 2007b). Thus, the bubble surface, which formed the bottom interface of the wetting film at the fluorite surface had the positive electrical charge.…”

Near-wall rising behaviour of a deformable bubble at high Reynolds number

“…On the other hand, the changes in the bubble-wall collision dynamics with wall boundary condition have been tested for the normal bouncing on a horizontal top-wall Zawala et al 2007). In these studies, the rising bubble was originally spherical and deformed only when it collided with the horizontal wall.…”

“…reported that air pockets trapped on a slippery wall cause the approaching bubble to attach on the wall after a smaller number of bounces than on a no-slip wall. Zawala et al (2007) estimated the transfer of kinetic energy to surface energy during those collisions. In the case of a hydrophobic surface, the energy transfer was small (i.e.…”

Bubble impingement and the mechanisms of heat transfer

“…Several studies have reported experimental results concerning impingement and subsequent bouncing of a single gas/vapour or liquid bubble on a wall in various fluids [3][4][5][6][7][8][9][10][11][12][13][14]. Many of these authors investigated bubble impact against deformable surfaces, such as the interface between water and air, where coalescence would most likely occur [3,4,[6][7][8]10], while the remaining authors have investigated the effect of a bubble bouncing against solid surfaces [5,9,[12][13][14].…”

“…Many of these authors investigated bubble impact against deformable surfaces, such as the interface between water and air, where coalescence would most likely occur [3,4,[6][7][8]10], while the remaining authors have investigated the effect of a bubble bouncing against solid surfaces [5,9,[12][13][14]. Tsao & Kock [5] observed the interaction between high Email address: donoghdb@tcd.ie (D.B.…”