[abstract] NUCLEATION FROM CAVITIES: EFFECTS OF CAVITY GEOMETRY

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[abstract] NUCLEATION FROM CAVITIES: EFFECTS OF CAVITY GEOMETRY

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Title: [abstract] NUCLEATION FROM CAVITIES: EFFECTS OF CAVITY GEOMETRY
Author: Chappell, MA; Payne, SJ
Abstract: BACKGROUND: The growth of pre-existing bubbles from cavities in the body may explain the production of some bubbles in the body under decompression. A conical crevice has previously been used as a simple model of such a nucleation site. However, real nucleation sites might take a wide range of geometries, e.g. the spherical shape of caveolae has been proposed as a potential source of intra-vascular bubbles. The analysis of nucleation from cavities becomes increasingly complex as the geometry deviates from that of a simple cone. In this work we examined the effect of cavity geometry using a simple analysis technique to gain an insight of its effect on the more general nucleation behaviouMATERIALS AND METHODS: The method of Atchley and Prosperetti (J. Acoust. Soc. Am. 86(3), 1989), for the analysis of nucleation from conical crevices assuming no transfer of gas, was generalised to any axially symmetric cavity geometry and four different cavity types compared. The restriction to no gas transfer was also relaxed by the inclusion of the transfer of fixed fractions of gas into the bubblRESULTS: The threshold for growth of the bubble both whilst inside and once it had emerged outside the cavity was considered. Once the bubble has emerged out of the cavity, the geometry of the cavity was found, in most cases, to be unimportant. Inside the cavity the threshold for growth required a smaller decompression for a spherical cavity as compared to crevice-like cavitieCONCLUSIONS: The spherical form of cavity is suitable for the growth of decompression bubbles and presents a smaller threshold for bubble growth than crevices. Once the bubble interface has emerged outside the cavity it can be treated as a bubble interface at a circular opening, the precise form of the geometry of the cavity being unimportant.
Description: Undersea and Hyperbaric Medical Society, Inc. (http://www.uhms.org )
URI: http://archive.rubicon-foundation.org/3699
Date: 2006

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  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

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