Magnetic resonance imaging of velocity fields, the void fraction and gas dynamics in a cavitating liquid

Mastikhin, Igor V.; Arbabi, Aidin; Newling, Benedict; Hamza, A. M.; Adair, Alexander

doi:10.1007/s00348-011-1209-9

Cited by 17 publications

(7 citation statements)

References 31 publications

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“…Ashokkumar (2011) recently reviewed this topic. Near the horn at maximum bubble concentration, the void fraction was as low as 5 Â 10 À4 with light diffraction and 5 Â 10 À3 with phase Doppler, whereas recent magnetic resonance imaging measurements (Mastikhin et al, 2012) proposed 8 Â 10 À3 in same conditions. The two techniques gave roughly consistent information: along the axis of a 13-mm ultrasonic horn, the mean bubble velocity clearly decreased from 1.5 m/s to a few centimeters per second at maximum US intensity (180 W), and the mean bubble diameter slightly decreasing with US power (from 40 μm at 40 W to about 10 μm at 180 W).…”

Section: Acoustic Cavitationmentioning

confidence: 85%

Ultrasonic mixing, homogenization, and emulsification in food processing and other applications

Delmas

Barthe

2015

Power Ultrasonics

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The use of power ultrasound (US) to intensify physicochemical processes is now a large area of research. The most famous application of high-power US is cleaning, but many other processes may be dramatically enhanced or qualitatively improved by ultrasonic irradiation. Various industrial fields are concerned as materials ([nano]materials, polymers, surface coatings, and electrochemistry), the environment (especially water, sludge, and soil treatments), and cosmetic and food engineering (mainly through extraction of natural products from plants, dissolution, homogenization, and emulsification processes). Among these various applications of power US the main unit operations most often involve multiphase media for either production and/or dispersion of a solid phase in a liquid through precipitation, crystallization, or simple deaggregation or disruption and/or dissolution of particles, floc, curd, and cells. These operations may be highly improved by power US.This chapter analyzes the effects of power US on such physical operations, excluding any reactive process. First, it has to be emphasized that hydrodynamics connected with power US does control its mechanical effects through acoustic cavitation, a key phenomenon, and through acoustic streaming, albeit to a much lesser extent. Thus a brief survey of cavitation and acoustic streaming gives the minimum information necessary to understand local and global US-induced hydrodynamics. As a direct consequence of acoustic cavitation and streaming, US mixing-both at a reactor scale (macromixing) and a molecular scale (micromixing)-is presented, with reference to the engineering approach linking cavitation and acoustic streaming phenomena to micro-and macromixing, respectively.Concerning specific US applications for solid-liquid suspensions, dispersion, or deagglomeration, the process of separating and suspending tiny particles that are initially naturally aggregated by attraction forces, is reviewed first. Then particle size reduction, achieved either by mechanical erosion/disruption or by dissolution, is detailed, including the combination of simultaneous disruption and dissolution. Rather similar applications concerning cells disruption and the dissolution of their organic content, especially for sludge treatment, are detailed. Finally, two main Power Ultrasonics. http://dx.

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Section: Acoustic Cavitationmentioning

confidence: 85%

Ultrasonic mixing, homogenization, and emulsification in food processing and other applications

Delmas

Barthe

2015

Power Ultrasonics

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“…To demonstrate the capabilities of MRV in opaque flows, two examples are shown here of its application to the flow through a venturi (with the aim to investigate cavitation). Recently, it was proposed that the technique can also quantify void fractions in, for example, cavitating flows [133,134]. Figure 8 shows 3D reconstructions of the cavitation cloud in a venturi.…”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Measurement in opaque flows: a review of measurement techniques for dispersed multiphase flows

Poelma

2020

Acta Mech

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A review is presented of measurement techniques to characterise dispersed multiphase flows, which are not accessible by means of conventional optical techniques. The main issues that limit the accuracy and effectiveness of optical techniques are briefly discussed: cross-talk, a reduced signal-to-noise ratio, and (biased) data drop-out. Extensions to the standard optical techniques include the use of fluorescent tracers, refractive index matching, ballistic imaging, structured illumination, and optical coherence tomography. As the first non-optical technique, a brief discussion of electrical capacitance tomography is given. While truly non-invasive, it suffers from a low resolving power. Ultrasound-based techniques have rapidly evolved from Doppler-based profiling to recent 2D approaches using feature tracking. The latter is also suitable for timeresolved flow studies. Magnetic resonance velocimetry can provide time-averaged velocity fields in 3D for the continuous phase. Finally, X-ray imaging is demonstrated to be an important tool to quantify local gas fractions. While potentially very powerful, the impact of the techniques will depend on the development of acquisition and measurement protocols for fluid mechanics, rather than for clinical imaging. This requires systematic development, aided by careful validation experiments. As theoretical predictions for multiphase flows are sparse, it is important to formulate standardised 'benchmark' flows to enable this validation.

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“…Bieberle et al have investigated two‐phase flows with MRI. The gas dynamics in a cavitating liquid including void fraction has been characterized in . Neacsu et al have studied the impregnation induced by capillarity across aligned cylinders.…”

Section: Introductionmentioning

confidence: 99%

Noninvasive 4D Flow Characterization in a Stirred Tank via Phase‐Contrast Magnetic Resonance Imaging

et al. 2017

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A noninvasive quantification of the hydrodynamics in a stirred tank in space and time using flow-sensitive phase-contrast magnetic resonance imaging (PC-MRI) at 7 Tesla (7 T) is demonstrated. The PC-MRI technique is able to characterize the unsteady periodic 3D flow velocities with acceptable spatial and temporal resolution and does not imply that optically transparent fluids are employed. PC-MRI is already widely used for medical diagnostics in order to determine the blood flow velocities, e.g., for cardiovascular applications. However, its utilization for engineering problems is still new, including process engineering. Therefore, it is important to check the suitability of PC-MRI to applications of practical interest in this field and complement other flow measurement and simulation techniques.

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Magnetic resonance imaging of velocity fields, the void fraction and gas dynamics in a cavitating liquid

Cited by 17 publications

References 31 publications

Ultrasonic mixing, homogenization, and emulsification in food processing and other applications

Ultrasonic mixing, homogenization, and emulsification in food processing and other applications

Measurement in opaque flows: a review of measurement techniques for dispersed multiphase flows

Noninvasive 4D Flow Characterization in a Stirred Tank via Phase‐Contrast Magnetic Resonance Imaging

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