Dynamics of bubbles and particles under the action of acoustic radiation force
Lev Ostrovsky, Senior Scientist
/NOAA Environmental Research Laboratory,聽
Date and time:聽
Friday, November 1, 2013 - 3:00pm
尝辞肠补迟颈辞苍:听
ECCR 245
础产蝉迟谤补肠迟:听
Studies of the dynamics of聽 small particles in hydrodynamic flows are聽 associated, among others, with a qualitative description of river meandering by Albert Einstein in 1920s. A complex particle dynamics can be induced by an oscillating acoustic field which produces聽 a period-averaged 鈥渞adiation force鈥� on particles and bubbles. This presentation outlines important peculiarities of such motions and some of their biomedical applications. In particular, dynamics of bubble ensembles results in a significant acoustic nonlinearity which can define, e.g., a mechanism of sound self-focusing. Hard particles and bubbles in a standing wave are concentrated in nodes of pressure or velocity, and their position can be controlled by changing frequency. Acoustic resonators are used for particle mixing and separation of cells and bacteria; these processes involve complex physical effects, such as the interplay between the radiation force and surface tension in fluids.