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Journal ArticleDOI

Umströmung kugelförmiger Blasen mit innerer Zirkulation

Udo Haas, +2 more
- 01 Sep 1972 - 
- Vol. 44, Iss: 18, pp 1060-1068
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TLDR
In this article, the authors untersuchten the differentialgleichungen, die das Geschwindigkeits- und Druckfeld in der Umgebung der Kugelblase beschreiben, berichtigen die vollstandigen Tragheitsglieder.
Abstract
Die Umstromung von einzelnen Kugelblasen mit innerer Zirkulation wurde theoretisch untersucht. Die Differentialgleichungen, die das Geschwindigkeits- und Druckfeld in der Umgebung der Blase beschreiben, berucksichtigen die vollstandigen Tragheitsglieder. Die Rechnungen haben ergeben, daszlig; sich die Stromung bis Re = 200 mit Sicherheit auf der Blasenruckseite nicht ablost. Es kommt vermutlich erst dann zu Ablosungen, wenn die Kugelblase deformiert wird, d. h. wenn die Kugelblase wegen Volumvergroszlig;erung in die Ellipsoidblase ubergeht. Die ablosungsfreie Umstromung der Kugelblase ist eine Folge der Beweglichkeit der Phasengrenzflache. Aus den berechneten Geschwindigkeits- und Druckverteilungen um die Blasen lieszlig;en sich die Widerstandsgesetze ermitteln, fur die einfache Gleichungen aufgestellt wurden. Sie werden durch die Ergebnisse experimenteller Untersuchungen sehr gut bestatigt. Die Gesetze werden mit bereits bekannten dazu verwendet, die Aufstiegsbewegung formbestandiger und formdynamischer Blasen in zusammenfassender Weise zu behandeln.

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Citations
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Journal ArticleDOI

Mass-transfer enhancement in single-drop extraction experiments

TL;DR: In this paper, it is shown that it is possible to describe nonstationary mass transfer between single drops and a continuous phase with a single parameter, the instability constant C IP, independent of both drop diameter and contact time between drop and continuous phase.
Journal ArticleDOI

Coalescence of two bubbles rising in line at low reynolds numbers

TL;DR: In this paper, the approach velocity of the following bubble ( u 2 ) is experimentally obtained and its behaviour with respect to the leading bubble velocity ( u 1 ) is examined.
Book ChapterDOI

Physicochemical hydrodynamics of Rising Bubble

TL;DR: In this paper, the authors discuss the physico-chemical hydrodynamics of a rising bubble and show that at small Reynolds numbers effective approximate analytical methods allow to characterize different states of dynamic adsorption layers quantitatively: weak retardation of the motion of bubble surfaces, almost complete reduction of bubble surface motion, transient state at a bubble surface between an almost completely retarded and almost completely free bubble surface.
Book ChapterDOI

Gas-Evolving Electrodes

H. Vogt
TL;DR: In a large number of relevant industrial processes, gases are generated by electrochemical reactions Processes linked to the evolution of gas exhibit some characteristics which are not typical of electrode processes in general Gas bubbles develop at bubble nuclei, grow in size, finally break off and rise in the liquid, thus providing a locally nonsteady state condition.
Journal ArticleDOI

Validated simulation of droplet sedimentation with finite-element and level-set methods.

TL;DR: In this paper, the simulation results were compared to experiments and empirical models in terms of droplet shape, oscillation behavior and terminal velocity, showing good agreement with the conventional finite-element method.
References
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Journal ArticleDOI

The boundary layer on a spherical gas bubble

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.
Journal ArticleDOI

Numerical Solution of the Three-Dimensional Equations of Motion for Laminar Natural Convection

Khalid Aziz, +1 more
- 01 Feb 1967 - 
TL;DR: In this paper, the complete Navier-Stokes equations are transformed and expressed in terms of vorticity and a vector potential, and solved using an alternating direction method for the parabolic portion of the problem, and successive over-relaxation for the elliptic portion.
Journal ArticleDOI

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.
Journal ArticleDOI

Mass transfer coefficients, velocities and shapes of carbon dioxide bubbles in free rise through distilled water

TL;DR: In this paper, the mass transfer coefficients of carbon dioxide bubbles in the size range 0·4 d e d e and 0.1 cm in equivalent spherical diameter were reported. But the shape of the bubble was also recorded at the instant its solution rate was being measured.
Journal ArticleDOI

The motion of gas bubbles rising through stagnant liquid

N. M. Aybers, +1 more
TL;DR: In this paper, the authors investigated the characteristics of gas bubbles in water in terms of bubble size and velocity, path, shape and drag characteristics, and determined the bubble's trajectory and size.