NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Nonlinear Bubble Interactions in Acoustic Pressure FieldsThe systems consisting of a two-phase mixture, as clouds of bubbles or drops, have shown many common features in their responses to different external force fields. One of particular interest is the effect of an unsteady pressure field applied to these systems, case in which the coupling of the vibrations induced in two neighboring components (two drops or two bubbles) may result in an interaction force between them. This behavior was explained by Bjerknes by postulating that every body that is moving in an accelerating fluid is subjected to a 'kinetic buoyancy' equal with the product of the acceleration of the fluid multiplied by the mass of the fluid displaced by the body. The external sound wave applied to a system of drops/bubbles triggers secondary sound waves from each component of the system. These secondary pressure fields integrated over the surface of the neighboring drop/bubble may result in a force additional to the effect of the primary sound wave on each component of the system. In certain conditions, the magnitude of these secondary forces may result in significant changes in the dynamics of each component, thus in the behavior of the entire system. In a system containing bubbles, the sound wave radiated by one bubble at the location of a neighboring one is dominated by the volume oscillation mode and its effects can be important for a large range of frequencies. The interaction forces in a system consisting of drops are much smaller than those consisting of bubbles. Therefore, as a first step towards the understanding of the drop-drop interaction subject to external pressure fluctuations, it is more convenient to study the bubble interactions. This paper presents experimental results and theoretical predictions concerning the interaction and the motion of two levitated air bubbles in water in the presence of an acoustic field at high frequencies (22-23 KHz).
Document ID
19970000447
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Barbat, Tiberiu
(State Univ. of New York Buffalo, NY United States)
Ashgriz, Nasser
(State Univ. of New York Buffalo, NY United States)
Liu, Ching-Shi
(State Univ. of New York Buffalo, NY United States)
Date Acquired
August 17, 2013
Publication Date
September 1, 1996
Publication Information
Publication: Third Microgravity Fluid Physics Conference
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
97N10414
Funding Number(s)
CONTRACT_GRANT: NAG3-1620
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available