Mechanics and mass transfer of single bubbles in free rise through some Newtonian and non-Newtonian liquids
TL;DR: In this paper, a constant volume technique is described for measuring the instantaneous rates of solution of rising gas bubbles in liquids; this simultaneously determines the bubble shape, area and rising velocity at the instant of measurement.
About: This article is published in Chemical Engineering Science.The article was published on 1970-02-01. It has received 149 citations till now. The article focuses on the topics: Bubble point & Bubble.
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Abstract: The formation of gas bubbles and their subsequent rise due to buoyancy are very important fundamental phenomena that contribute significantly to the hydrodynamics in gas−liquid reactors. The rise o...
657 citations
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09 Jan 2004
TL;DR: In this paper, Sea salt aerosol (SSA) particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of other aerosols and more broadly influencing the geochemical cycles of substances with which they interact.
Abstract: Sea salt aerosol (SSA) exerts a major influence over a broad reach of geophysics. It is important to the physics and chemistry of the marine atmosphere and to marine geochemistry and biogeochemistry generally. It affects visibility, remote sensing, atmospheric chemistry, and air quality. Sea salt aerosol particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of these other aerosols and more broadly influencing the geochemical cycles of substances with which they interact. As the key aerosol constituent over much of Earth's surface at present, and all the more so in pre-industrial times, SSA is central to description of Earth's aerosol burden.
603 citations
TL;DR: In this article, a bubble model was developed to examine the sensitivity of bubble-mediated CH4 transport to several environmental parameters, such as the release depth, bubble size, dissolved gas concentrations, temperature, surface active substances, and bulk fluid motions.
288 citations
TL;DR: In this paper, a gas-liquid contactor with nonwetted microporous fibres in the laminar flow regime was studied and the active mass transfer area was found to be equal to the total membrane area, regardless the porosity of the fibres.
212 citations
TL;DR: The measurements described here reveal the unexpected result that the liquid velocity behind the bubbles is in the downwards direction away from the rising bubbles, which is called the phenomenon ‘negative wake’.
Abstract: GAS bubbles rising by gravity in non-newtonian elastic liquids1–4 are different to gas bubbles in viscous newtonian fluids in at least two ways. First, the bubbles in the non-newtonian liquids often have a peculiar tip at the rear pole, and second, the terminal rise velocity versus volume curve often has a discontinuity at a certain ‘critical’ volume. To investigate this unusual flow situation further we have used laser–Doppler anemometry5 to measure the liquid velocity in the wake behind air bubbles in a non-newtonian liquid. The measurements described here reveal the unexpected result that the liquid velocity behind the bubbles is in the downwards direction away from the rising bubbles (the velocities are referred to an observer at rest with respect to the liquid far from the bubbles). Thus the liquid velocity is opposite to the velocity in the usual wake behind objects moving in viscous newtonian fluids and we have called the phenomenon ‘negative wake’.
191 citations
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TL;DR: In this article, the boundary layer on a spherical gas bubble rising steadily through liquid of small viscosity is derived and the equations are linear are linear and are solved in closed form; the value obtained is 12πaaUμ, where a is the bubble radius and U the terminal velocity.
Abstract: The equations governing the boundary layer on a spherical gas bubble rising steadily through liquid of small viscosity are derived. These equations are linear are linear and are solved in closed form. The boundary layer separates at the rear stagnation point of the bubble to form a thin wake, whose structure is determined. Thus the drag force can be calculated from the momentum defect. The value obtained is 12πaaUμ, where a is the bubble radius and U the terminal velocity, and this agrees with the result of Levich (1949) who argued from the viscous dissipation in the potential flow round the bubble. The next term in an expansion of the drag in descending fractional powers of R is found and the results compared with experiment.
478 citations
TL;DR: In this article, a form and Geschwindigkeit einer in einem vertikalen Rohr aufsteigenden, unendlich langen Luftblase zu finden, fuhrt unter Vernachlassigung der Kapillar-and Zahigkeitskrafte auf ein Eigenwertproblem der Differentialgleichung Δφ=0, das in erster Annaherung unter der der Wirklichkeit gut entsprechenden Ann
Abstract: Die Aufgabe: Form und Geschwindigkeit einer in einem vertikalen Rohr aufsteigenden, unendlich langen Luftblase zu finden, fuhrt unter Vernachlassigung der Kapillar- und Zahigkeitskrafte auf ein Eigenwertproblem der Differentialgleichung Δφ=0, das in erster Annaherung unter der der Wirklichkeit gut entsprechenden Annahme gelost wird, das der Meridianschnitt der Blase in der Umgebung der Kuppe durch den Krummungskreis ersetzt werden kann. Der Eigenwert, der sich als Funktion dieses Krummungsradius angeben last, wird dadurch bestimmt, das die asymptotische Losung mit stetiger Tangente in den Krummungskreis ubergehen soll. Berechneter und experimentell gefundener Wert stimmen gut uberein.
355 citations
TL;DR: Theoretical equations are developed to describe mass transfer around any solid or rapidly circulating axisymmetric body of revolution as discussed by the authors, which apply only when the Peclet and Schmidt numbers are large in value.
262 citations
TL;DR: In this paper, the authors reported experimental values and semi-theoretical formulae for the rates of solution of drops and bubbles under forced convection conditions, and discussed the effect of surface active agents on the mass transfer rate.
121 citations
TL;DR: In this article, the time dependent convective-diffusion equations for mass transfer between a drop and a continuous phase are solved by means of a similarity variable ηi = yδi(θ, t).
111 citations