Growth and collapse of a vapor bubble in a narrow tube

Abstract

The uid mechanical aspects of the axisymmetric growth and collapse of a bubble in a narrow tube lled with a viscous liquid are studied numerically. The tube is open at both ends and connects two liquid reservoirs at constant pressure. The bubble is initially a small sphere and growth is triggered by a large internal pressure applied for a short time. After this initial phase, the motion proceeds by inertia. This model simulates the e ect of an intense, localized, brief heating of the liquid which leads to the nucleation and growth of a bubble. The dimensionless parameters governing the problem are discussed and their e ects illustrated with several examples. It is also shown that, when

Acoustic response of compliable microvessels containing ultrasound contrast agents

“…However, this would appear to be a poor description of the conditions in small blood vessels and capillaries which constrain oscillation. Recently, increasing attention has been directed to the effect of small vessels on the microbubble's oscillation (Yuan et al 1999;Ory et al 2000;Sassaroli and Hynynen 2004;Hu et al 2005;Sassaroli and Hynynen 2005). In these models, the microvessel is usually simplified as a rigid tube and distinct characteristics observed for a microbubble's oscillation in a tube as compared with oscillation in an unbounded field or in large vessels.…”

Vapor bubbles in confined geometries : a numerical study

“…The final shape is oblate and the motion remains very nearly one-dimensional until the very end because surface tension does not have the time to make the interface curved. Thus, the flow retains its approximately one-dimensional nature due to its brief duration [56], which makes a one-dimensional model a reasonable approximation.…”

“…The early models [15,56,68,71] of these processes assumed that the high vapor pressure in the bubble caused by the initial heat pulse persisted only for a very short time and the subsequent dynamics was mostly governed by inertial and viscous effects. We find that these essentially mechanical models are inadequate to describe the observations and develop a new model which incorporates thermal effects.…”

“…In [56,57] the growth and collapse of a vapor bubble in a narrow tube were studied by means of a front tracking method. The thermal aspects of the problem however were neglected: the bubble growth was initiated by applying a pressure pulse.…”

“…For example, the high liquid velocity induced by transient bubbles has been used to provide high-Reynolds number flow in microsystems [19]. [67] and [56] have studied the dynamics of highly transient vapor bubbles in a tube and have demonstrated a pumping effect [15,68]; see also [69,70].…”