Characterization of Bubble Shapes in Non‐Newtonian Fluids by Parametric Equations

Xu, Feishi; Midoux, N.; Li, Huai Z.; Hébrard, Gilles; Dietrich, Nicolas

doi:10.1002/ceat.201800690

Cited by 9 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By varying the concentrations and temperature, they identified various regimes, including those without a cusp, steady cusp and oscillatory bubbles. Xu et al [39] devised a regime map illustrating different dynamics of an air bubble rising in PAAm and xanthan gum in the Reynolds number and Eötvös-Bond number space. By varying the air bubble volume, Polyres & Vidal [40] observed a small spherical bubble, a bubble exhibiting a cusp at its rear, bubble deflection and bubble fragmentation with a fingering instability.…”

Section: Bubble Shapementioning

confidence: 99%

Bubble ascent and rupture in mud volcanoes

Rudolph,

Sahu,

Savva

et al. 2024

R. Soc. Open Sci.

View full text Add to dashboard Cite

Large gas bubbles can reach the surface of pools of mud and lava where they burst, often through the formation and expansion of circular holes. Bursting bubbles release volatiles and generate spatter, and hence play a key role in volcanic degassing and volcanic edifice construction. Here, we study the ascent and rupture of bubbles using a combination of field observations at Pâclele Mici (Romania), laboratory experiments with mud from the Imperial Valley (California, USA), numerical simulations and theoretical models. Numerical simulations predict that bubbles ascend through the mud as elliptical caps that develop a dimple at the apex as they impinge on the free surface. We documented the rupture of bubbles in nature and under laboratory conditions using high-speed video. The bursting of mud bubbles starts with the nucleation of multiple holes, which form at a near-constant rate and in quick succession. The quasi-circular holes rapidly grow and coalesce, and the sheet evolves towards a filamentous structure that finally falls back into the mud pool, sometimes breaking up into droplets. The rate of expansion of holes in the sheet can be explained by a generalization of the Taylor–Culick theory, which is shown to hold independent of the fluid rheology.

show abstract

Section: Bubble Shapementioning

confidence: 99%

Bubble ascent and rupture in mud volcanoes

Rudolph,

Sahu,

Savva

et al. 2024

R. Soc. Open Sci.

View full text Add to dashboard Cite

show abstract

“…[27,29,30] It is important to note that the shape of rising gas bubbles typically deforms and stretches when surrounded by a pseudoplastic fluid. [31][32][33][34] Although similar variations in bubble shape are expected in yieldpseudoplastic mixing systems, the bubbles were simplified as spherical. This simplification is commonly employed in the literature when investigating gas dispersion in non-Newtonian fluids.…”

Section: Computational Fluid Dynamics (Cfd)mentioning

confidence: 99%

Effect of agitation and aeration on gas dispersion efficiency in coaxial mixers containing yield‐pseudoplastic fluids: Experimental and numerical analysis

Barros,

Ein‐Mozaffari,

Lohi

2023

Can J Chem Eng

View full text Add to dashboard Cite

Aerated stirred vessels are commonly employed to enhance gas dispersion. However, the associated high energy consumption is a challenging feature, particularly when dealing with complex non‐Newtonian fluids. Coaxial mixers comprising a central impeller and a close‐clearance impeller have emerged as an energy‐efficient alternative that effectively intensifies gas dispersion. Hence, the objective of this study is to investigate the effect of aeration and agitation on the gas dispersion effectiveness of a coaxial mixer containing a yield‐pseudoplastic fluid. An anchor‐pitched blade turbine was employed to disperse air into a 1 wt.% xanthan gum solution, and the analysis primarily focused on characterizing the gas holdup and fluid flow behaviour. Gas holdup data were obtained experimentally using electrical resistance tomography (ERT), while computational fluid dynamics (CFD) simulations provided a detailed analysis of fluid flow patterns within the coaxial mixer. The rotational speed of the impeller exhibited a non‐monotonic effect on the gas holdup, and a significant influence of the interaction between variables was identified. For instance, the experimental data showed that the aeration effect varied with the anchor speed. Nevertheless, the variables' interaction effect was explained by the change in flow pattern observed numerically. Furthermore, the CFD results demonstrated that high gas holdup does not necessarily indicate intensified mixing. Therefore, combining experimental data and numerical simulations enables a more accurate characterization of mixing performance. These findings contribute to the understanding and improvement of mixing performance in such a complex system, which is crucial for designing efficient operations.

show abstract

“…Based on the reduction of the colorimetric indicator (resorufin) in presence of oxygen, Dietrich and Hébrard [42] estimated the liquid-side mass transfer coefficient around a freely rising bubble and the result proved that the colorimetric technique had the potential to provide new, detailed insight into the spatiotemporal dynamics of the mass transfer of rising gas bubbles. More recently, the PLIF-I technique was applied to a non-Newtonian fluid to study the impact of fluid properties on the mass transfer coefficient [43,44].…”

Section: Application Of the Visualization Techniques To Gas-liquid Systemsmentioning

confidence: 99%

Comparison of three different techniques for gas-liquid mass transfer visualization

Hébrard

Dietrich

2020

International Journal of Heat and Mass Transfer

Self Cite

View full text Add to dashboard Cite

In this article three different techniques for visualizing gas-liquid mass transfer are reviewed according to their applications in air-water systems. The three techniques are: Planar Laser Induced Fluorescence (PLIF with the use of fluorescent resorufin), PLIF with Inhibition (PLIF-I with the use of a ruthenium complex), and a colorimetric technique (using a redox reaction with the pink-colored dye resorufin).For comparison purpose, the three techniques were conducted in the same experimental set-up to characterize the local oxygen mass transfer from a single air bubble (with equivalent diameter ~1 mm) rising in water. This paper rigorously compares these three techniques and aims to point out their advantages and limitations. The comparison was divided into two parts: the visualization and the quantification of the mass transfer. The discussion focused on the image quality, the required equipment, and the accuracy of the quantification results including the mass flux, the diffusion coefficient and the mass transfer coefficient. A guideline was provided for choosing the technique that most accurately visualizes and characterizes the local mass transfer in gas-liquid systems.

show abstract

Characterization of Bubble Shapes in Non‐Newtonian Fluids by Parametric Equations

Cited by 9 publications

References 37 publications

Bubble ascent and rupture in mud volcanoes

Bubble ascent and rupture in mud volcanoes

Effect of agitation and aeration on gas dispersion efficiency in coaxial mixers containing yield‐pseudoplastic fluids: Experimental and numerical analysis

Comparison of three different techniques for gas-liquid mass transfer visualization

Contact Info

Product

Resources

About