title: Jets and sprays arising from a spark-induced oscillating bubble near a plate with a hole.
abstract: An experimental study of jets and sprays formed by a spark-induced bubble collapsing near a plate with a hole is presented. A Perspex plate with a hole at its center is placed in a half-filled water tank with its top face near the air-water interface. A bubble is created using a low-voltage electrical spark below the hole in the plate. The bubble expands against the hole, which pushes the liquid present within the hole and leads to an initial primary jet of water that emerges from the other end of the hole into air. The bubble subsequently collapses and leads to a second jet that is characterized by short bursts of liquid spray followed by a thicker continuous liquid column. The impact of the sprays onto the primary jet leads to perturbations in the jet and the breakup of the latter into fine droplets. The entire phenomenon is recorded using a high-speed camera to visualize the mechanism both within and outside the hole. The results give a clearer indication of the mechanism behind a recently reported phenomenon on the formation of impacting jets caused by bubble expansion and collapse at the micrometer length scale. The variation of the jet characteristics with parameters such as the position of the water-air interface with respect to the plate and the hole geometry (i.e., the hole diameter and the plate thickness) is also presented.
authors.affiliation: NUS Graduate School for Integrative Sciences and Engineering, Center for Life Sciences, 28 Medical Drive, Singapore.
authors.forename: Badarinath
authors.initials: B
authors.lastname: Karri
authors.forename: Siew-Wan
authors.initials: SW
authors.lastname: Ohl
authors.forename: Evert
authors.initials: E
authors.lastname: Klaseboer
authors.forename: Claus-Dieter
authors.initials: CD
authors.lastname: Ohl
authors.forename: Boo Cheong
authors.initials: BC
authors.lastname: Khoo
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry*; D006358:Hot Temperature; D045423:Microbubbles; D008956:Models, Chemical; D012212:Rheology / Q000379:methods*; D014732:Vibration
chemical_list: D005740:Gases