scholarly journals Influence of Temperature on Rising Bubble Dynamics in Water and n-pentanol Solutions

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1067
Author(s):  
Mariusz Borkowski ◽  
Jan Zawala
Keyword(s):  
Bubble Dynamics ◽  
Terminal Velocity ◽  
Bubble Surface ◽  
Ultrasonic Sensor ◽  
Bubble Velocity ◽  
Pure Liquid ◽  
Equivalent Radius ◽  
Influence Of Temperature ◽  
Rising Bubble ◽  
Influence Of Water

Data in the literature on the influence of water temperature on the terminal velocity of a single rising bubble are highly contradictory. Different variations in bubble velocity with temperature are reported even for potentially pure systems. This paper presents a systematic study on the influence of temperature between 5 °C and 45 °C on the motion of a single bubble of practically constant size (equivalent radius 0.74 ± 0.01 mm) rising in a clean water and n-pentanol solution of different concentrations. The bubble velocity was measured by a camera, an ultrasonic sensor reproduced in numerical simulations. Results obtained by image analysis (camera) were compared to the data measured by an ultrasonic sensor to reveal the similar scientific potential of the latter. It is shown that temperature has a significant effect on the velocity of the rising bubble. In pure liquid, this effect is caused only by modifying the physicochemical properties of the water phase, not by changing the hydrodynamic boundary conditions at the bubble surface. In the case of the solutions with surface-active substances, the temperature-change kinetics of the dynamic adsorption layer formation facilitate the immobilization of the liquid/gas interface.

Bubble velocity profile and model of surfactant mass transfer to bubble surface

2001 ◽  
Vol 56 (23) ◽  
pp. 6605-6616 ◽  
Author(s):  
Yongqin Zhang ◽  
J.B McLaughlin ◽  
J.A Finch
Keyword(s):  
Mass Transfer ◽  
Velocity Profile ◽  
Bubble Surface ◽  
Bubble Velocity

scholarly journals Bubble Dynamics in Soft and Biological Matter

2019 ◽  
Vol 51 (1) ◽  
pp. 331-355 ◽  
Author(s):  
Benjamin Dollet ◽  
Philippe Marmottant ◽  
Valeria Garbin
Keyword(s):  
Viscoelastic Medium ◽  
Bubble Dynamics ◽  
Nonlinear Behavior ◽  
Bubble Surface ◽  
Solid Particles ◽  
Advanced Materials ◽  
Viscoelastic Layer ◽  
Future Research ◽  
Oscillatory Dynamics ◽  
Biological Matter

Bubbles are present in a large variety of emerging applications, from advanced materials to biology and medicine, as either laser-generated or acoustically driven bubbles. In these applications, the bubbles undergo oscillatory dynamics and collapse inside—or near—soft and biological materials. The presence of a soft, viscoelastic medium strongly affects the bubble dynamics, both its linear resonance properties and its nonlinear behavior. Surfactant molecules or solid particles adsorbed on a bubble surface can also modify the bubble dynamics through the rheological properties of the interfacial layer. Furthermore, the interaction of bubbles with biological cells and tissues is highly dependent on the mechanical properties of these soft deformable media. This review covers recent developments in bubble dynamics in soft and biological matter for different confinement conditions: bubbles in a viscoelastic medium, coated by a viscoelastic layer, or in the vicinity of soft confinement or objects. The review surveys current work in the field and illustrates open questions for future research.

Numerical Simulations of Dynamics and Heat Transfer Associated With a Single Bubble in the Presence of Noncondensables

2007 ◽  
Author(s):  
Jinfeng Wu ◽  
Vijay K. Dhir
Keyword(s):  
Heat Transfer ◽  
Bubble Dynamics ◽  
Numerical Procedure ◽  
Saturation Temperature ◽  
Bubble Surface ◽  
Moving Mesh Method ◽  
Bubble Liquid ◽  
Noncondensable Gas ◽  
Noncondensable Gases ◽  
Level Set Function

Under subcooled boiling conditions, the liquid may contain dissolved noncondensabe gases. During phase change at the bubble-liquid interface, noncondensable gases will be injected into the bubble along with vapor. Due to heat transfer into sub-cooled liquid, vapor will condense in the upper regions of the bubble and the bubble interface is impermeable to noncondensables. As a result, noncondensabe gases will accumulate at the top of bubbles. This existing gradient of noncondensable concentration inside bubble determines the saturation temperature gradient around the bubble surface. The nonuniform saturation temperature may cause a difference in surface tension which would give rise to thermocapillary convection in the vicinity of the interface. So far, this description is merely a hypothesis. It is felt that much inspection is in vital demand to clarify the uncertainty as to the role of noncondensables throughout this process. In this study, air is taken as noncondensable gas, and the aim is to investigate the effects of noncondensable air on heat transfer and bubble dynamics. The results from a numerical procedure coupling level set function with moving mesh method show the evidence of effects of noncondensable air imposed on heat transfer and the induced flow pattern is presented as well.

Velocity fluctuations in a homogeneous dilute dispersion of high-Reynolds-number rising bubbles

2002 ◽  
Vol 453 ◽  
pp. 395-410 ◽  
Author(s):  
FRÉDÉRIC RISSO ◽  
KJETIL ELLINGSEN
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Liquid Velocity ◽  
Liquid Volume ◽  
Equivalent Radius ◽  
Velocity Fluctuations ◽  
Rising Bubble ◽  
High Reynolds ◽  
Conditional Statistics ◽  
Gas Volume

An experimental investigation of a homogeneous swarm of rising bubbles is presented. The experimental arrangement ensures that all the bubbles have the same equivalent radius, a = 1.25 mm. This particular size corresponds to high-Reynolds-number ellipsoidal rising bubbles. The gas volume fractions α is small, ranging from 0.5 to 1.05%. The results are compared with the reference situation of a single rising bubble, which was investigated in a previous work. From the use of conditional statistics, the existence of two regions in which the liquid velocity fluctuations are of a different nature are distinguished. In the vicinity of the bubbles, the liquid fluctuations are the same as those measured close to a single rising bubble. They therefore do not depend on α. Far from the bubble, the liquid fluctuations are controlled by the nonlinear interactions between the wakes of all the bubbles. Their probability density function scales as α0.4, exhibiting a self-similar behaviour. The total fluctuation combines the contributions of these two regions weighted by the fraction of the liquid volume they occupy. The contribution of the bubble vicinity is thus shown to vary linearly with α while the wake contribution does not. Both are non-isotropic since strong upward vertical fluctuations are more probable.

Measurements of the Terminal Velocity of Bubbles Rising in a Chain

1973 ◽  
Vol 95 (1) ◽  
pp. 17-22 ◽  
Author(s):  
C. H. Marks
Keyword(s):  
Bubble Size ◽  
Tap Water ◽  
Bubble Radius ◽  
Terminal Velocity ◽  
Bubble Velocity ◽  
Distilled Water ◽  
Rise Velocity ◽  
Sugar Water ◽  
A Chain ◽  
Made In

Measurements were made of the effect of frequency of formation on the velocity of air bubbles rising in a chain through distilled water, lap water, and sugar water. In all cases, increasing the frequency increased the rise velocity for a given bubble size. Measurements made in distilled water showed that the increase of velocity with frequency dropped off with bubble size until it was negligible for the smaller bubbles. It was shown that the variation of bubble velocity with frequency and size can be fairly well correlated with the velocity of rise of solitary bubbles by means of a model based on turbulent wake theory. Tap-water measurements showed the same effect of impurities in the water on the bubble rise velocity as had been observed for solitary bubbles; however, the bubble radius at which the effect became apparent decreased with frequency. Measurements made in sugar water showed that the effect of fluid properties on the rise velocity decreased as frequency increased. At the highest frequencies, no difference could be seen between the distilled water and the sugar water rise velocity curves.

An Experimental Investigation for Bubble Rising in Non-Newtonian Fluids and Empirical Correlation of Drag Coefficient

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Fan Wenyuan ◽  
Ma Youguang ◽  
Jiang Shaokun ◽  
Yang Ke ◽  
Li Huaizhi
Keyword(s):  
Reynolds Number ◽  
Aqueous Solutions ◽  
Drag Coefficient ◽  
Bubble Diameter ◽  
Video Camera ◽  
Solution Concentration ◽  
Terminal Velocity ◽  
Newtonian Fluids ◽  
Rising Bubble ◽  
Moderate Reynolds Number

The velocity, shape, and trajectory of the rising bubble in polyacrylamide (PAM) and carboxymethylcellulose (CMC) aqueous solutions were experimentally investigated using a set of homemade velocimeters and a video camera. The effects of gas the flowrate and solution concentration on the bubble terminal velocity were examined respectively. Results show that the terminal velocity of the bubble increases with the increase in the gas flowrate and the decrease in the solution concentration. The shape of the bubble is gradually flattened horizontally to an ellipsoid with the increase in the Reynolds number (Re), Eötvös number (Eo), and Morton number (Mo). With the increase in the Re and Eo, the rising bubble in PAM aqueous solutions begin to oscillate, but there is no oscillation phenomena for CMC aqueous solutions. By dimensional analysis, the drag coefficient of a single bubble in non-Newtonian fluids in a moderate Reynolds number was correlated as a function of Re, Eo, and Archimedes number (Ar) based on the equivalent bubble diameter. The predicted results by the present correlation agree well with the experimental data.

scholarly journals Computational analysis of single rising bubbles influenced by soluble surfactant

2018 ◽  
Vol 856 ◽  
pp. 709-763 ◽  
Author(s):  
Chiara Pesci ◽  
Andre Weiner ◽  
Holger Marschall ◽  
Dieter Bothe
Keyword(s):  
Bubble Dynamics ◽  
Solution Procedure ◽  
Bubble Surface ◽  
Fluid Interfaces ◽  
Arbitrary Lagrangian Eulerian ◽  
Deformable Interface ◽  
Mesh Resolution ◽  
Surfactant Transport ◽  
Physical Phenomena ◽  
Soluble Surfactant

This paper presents novel insights into the influence of soluble surfactants on bubble flows obtained by direct numerical simulation (DNS). Surfactants are amphiphilic compounds which accumulate at fluid interfaces and significantly modify the respective interfacial properties, influencing also the overall dynamics of the flow. With the aid of DNS, local quantities like the surfactant distribution on the bubble surface can be accessed for a better understanding of the physical phenomena occurring close to the interface. The core part of the physical model consists of the description of the surfactant transport in the bulk and on the deformable interface. The solution procedure is based on an arbitrary Lagrangian–Eulerian (ALE) interface-tracking method. The existing methodology was enhanced to describe a wider range of physical phenomena. A subgrid-scale (SGS) model is employed in the cases where a fully resolved DNS for the species transport is not feasible due to high mesh resolution requirements and, therefore, high computational costs. After an exhaustive validation of the latest numerical developments, the DNS of single rising bubbles in contaminated solutions is compared to experimental results. The full velocity transients of the rising bubbles, especially the contaminated ones, are correctly reproduced by the DNS. The simulation results are then studied to gain a better understanding of the local bubble dynamics under the effect of soluble surfactant. One of the main insights is that the quasi-steady state of the rise velocity is reached without ad- and desorption being necessarily in equilibrium.

Bubble Shape in Non-Newtonian Fluids

2002 ◽  
Vol 69 (5) ◽  
pp. 703-704 ◽  
Author(s):  
D. De Kee and ◽  
C. F. Chan Man Fong ◽  
J. Yao
Keyword(s):  
Newtonian Fluid ◽  
Bubble Dynamics ◽  
Complex Fluids ◽  
Newtonian Fluids ◽  
Bubble Velocity ◽  
Bubble Shape ◽  
Surfactant Effects

The study of the behavior of bubbles in complex fluids is of industrial as well as of academic importance. Bubble velocity-volume relations, bubble shapes, as well as viscous, elastic, and surfactant effects play a role in bubble dynamics. In this note we extend the analysis of Richardson to a non-Newtonian fluid.

Visualization of Micro-Scale Bubble Dynamics in Pure Liquids and Aqueous Surfactant Solutions

Volume 4 ◽  
2004 ◽  
Author(s):  
S. Sethu Raghavan ◽  
Raj M. Manglik
Keyword(s):  
Bubble Dynamics ◽  
Bubble Diameter ◽  
Dynamic Surface Tension ◽  
Bubble Surface ◽  
Dimethyl Formamide ◽  
Time Interval ◽  
Dynamic Surface ◽  
Micro Scale ◽  
Surfactant Solutions ◽  
Air Interface

Growth and departure of a single adiabatic bubble in pure liquids and aqueous surfactant solutions is visualized. High-resolution photographic records are obtained that characterize the micro-scale bubble dynamics (shape, size, and post-departure translation), the mean bubble diameter at different time periods of its growth and departure, and the bubble surface age (the time interval from the newly formed interface to the attainment of departure diameter). This pre- and post-departure dynamics of air bubbles is visualized in water, N, N dimethyl-formamide (DMF), and ethyl alcohol (all pure liquids), and aqueous surfactant solutions of SDS (1250 wppm, 2500 wppm, and 5000 wppm), CTAB (200 wppm), and Triton X-305 (1000 wppm). The evolution of different bubble shapes, sizes, and departure frequencies is presented to highlight the effects of surface-active forces. In the case of surfactant solutions, the dynamic effects of the molecular-scale adsorption-desorption dynamics of the additive at the liquid-air interface that manifests in the dynamic surface tension is also delineated.

Effects of Pine Oil on Dynamics of Bubble in Froth Flotation

2014 ◽  
Vol 493 ◽  
pp. 155-160 ◽  
Author(s):  
Warjito ◽  
Indra Pranata Al Kautsar
Keyword(s):  
Bubble Dynamics ◽  
Froth Flotation ◽  
Terminal Velocity ◽  
Image Capture ◽  
Flotation Column ◽  
Pine Oil ◽  
Modify Surface ◽  
Three Stages ◽  
Processing Software ◽  
Bubble Movement

Dynamics of bubble in froth flotation have been studied. The purpose of this research is to study the effects of pine oil on the dynamics of small bubble in froth flotation. Dynamics of bubble is an important parameter which determines flotation eficiency. Acrylic pipe was setup as a flotation column and equipped with image capture and lighting equipments. Later on, bubble was generated by a nozzle. A different nozzle size and pine oil concentrations were used in this experiment. Eventually, the dynamics of the bubble were captured by camera and the images were then processed by image processing software. Therefore, bubbles size and its position can be determined. The results indicate that bubble movement can be divided into three stages: acceleration, deceleration and terminal velocity. It is also indicated that pine oil modify surface tension; hence the bubble size become smaller and its velocy decrease. Moreover, pine oil induces the bubble to reach terminal velocity faster then bubble in water wthout pine oil. Therefore, it can be concluded that pine oil affects bubble dynamics significantly.

Sign in / Sign up

Export Citation Format

Share Document