Gotowe bibliografie tematyczne / Newtonian bubble / Artykuły w czasopismach

Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Newtonian bubble.

Artykuły w czasopismach na temat „Newtonian bubble”

Autor: Grafiati

Data publikacji: 6 września 2023

Data aktualizacji: 19 lipca 2025

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych

Wybierz rodzaj źródła:

Sprawdź 50 najlepszych artykułów w czasopismach naukowych na temat „Newtonian bubble”.

Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.

Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.

Przeglądaj artykuły w czasopismach z różnych dziedzin i twórz odpowiednie bibliografie.

Rosenbaum, Eilis, Mehrdad Massoudi, and Kaushik Dayal. "Surfactant stabilized bubbles flowing in a Newtonian fluid." Mathematics and Mechanics of Solids 24, no. 12 (2019): 3823–42. http://dx.doi.org/10.1177/1081286519854508.

Pełny tekst źródła

Streszczenie:

Bubbles suspended in a fluid cause the suspension to have different rheological properties than the base fluid. In general, the viscosity of the suspension increases as the volume fraction of the bubbles is increased. A current application, and motivation for this study, is in wellbore cements used for hydrocarbon extraction and carbon sequestration. In these settings, the gas bubbles are dispersed into the cement to reduce the density as well as improve the properties for specific conditions or wellbore issues. In this paper, we use Stokesian dynamics to numerically simulate the behavior of a large number of bubbles suspended in a Newtonian fluid. Going beyond prior work on simulating particles in suspension, we account for the nature of bubbles by allowing for slip on the bubble surface, the deflection on the bubble surface, and a bubble–bubble pairwise interaction that represents the surfactant physics; we do not account for bubble compressibility. We incorporate these interactions and simulate bubble suspensions of monodisperse size at several volume fractions. We find that the bubbles remain better dispersed compared with hard spherical particles that show a greater tendency to structure or cluster.

Style APA, Harvard, Vancouver, ISO itp.

De Kee and, D., C. F. Chan Man Fong, and J. Yao. "Bubble Shape in Non-Newtonian Fluids." Journal of Applied Mechanics 69, no. 5 (2002): 703–4. http://dx.doi.org/10.1115/1.1480822.

Pełny tekst źródła

Streszczenie:

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.

Style APA, Harvard, Vancouver, ISO itp.

Kontaxi, Georgia, Yorgos G. Stergiou, and Aikaterini A. Mouza. "Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid." Micromachines 12, no. 1 (2021): 71. http://dx.doi.org/10.3390/mi12010071.

Pełny tekst źródła

Streszczenie:

Over the last few years, microbubbles have found application in biomedicine. In this study, the characteristics of bubbles formed when air is introduced from a micro-tube (internal diameter 110 μm) in non-Newtonian shear thinning fluids are studied. The dependence of the release time and the size of the bubbles on the gas phase rate and liquid phase properties is investigated. The geometrical characteristics of the bubbles are also compared with those formed in Newtonian fluids with similar physical properties. It was found that the final diameter of the bubbles increases by increasing the gas flow rate and the liquid phase viscosity. It was observed that the bubbles formed in a non-Newtonian fluid have practically the same characteristics as those formed in a Newtonian fluid, whose viscosity equals the asymptotic viscosity of the non-Newtonian fluid, leading to the assumption that the shear rate around an under-formation bubble is high, and the viscosity tends to its asymptotic value. To verify this notion, bubble formation was simulated using Computational Fluid Dynamics (CFD). The simulation results revealed that around an under-formation bubble, the shear rate attains a value high enough to lead the viscosity of the non-Newtonian fluid to its asymptotic value.

Style APA, Harvard, Vancouver, ISO itp.

Pełny tekst źródła

Streszczenie:

Style APA, Harvard, Vancouver, ISO itp.

Long, Li. "Simulation analysis of bubble coalescence behavior characteristics in Newtonian fluids based on the phase field method." Journal of Physics: Conference Series 2707, no. 1 (2024): 012123. http://dx.doi.org/10.1088/1742-6596/2707/1/012123.

Pełny tekst źródła

Streszczenie:

Abstract Gas-liquid two-phase flow is widely used in various fields of chemical production because of its stability. The bubble coalescence behavior significantly impacts bubbles’ size, shape, and movement. These parameters are essential for interphase mass, heat transfer processes, and equipment performance. This paper presents a simulation study of the bubble coalescence behavior of Newtonian fluids using the phase field method through simulation software. The relative location of bubbles were divided into three types: vertical, parallel and random; and also the distribution of bubbles can be divided into three cases: symmetric, left-skewed and right-skewed. This paper focuses on the influence of the arrangements of the bubbles on their coalescence behavior in Newtonian fluids. The results show that the relative distance of bubbles is the crucial factor for the occurrence of bubble coalescence in Newtonian fluids, and different distributions show different laws on the motion of bubbles.

Style APA, Harvard, Vancouver, ISO itp.

Shan, Jie, and Xiaojun Zhou. "The Effect of Bubbles on Particle Migration in Non-Newtonian Fluids." Separations 8, no. 4 (2021): 36. http://dx.doi.org/10.3390/separations8040036.

Pełny tekst źródła

Streszczenie:

The movement of the gas–liquid interface caused by the movement of the bubble position will have an impact on the starting conditions for particle migration. This article quantifies the influence of moving bubbles on the starting conditions of particle migration in non-Newtonian fluids, and it aims to better understand the influence of bubbles moving in non-Newtonian fluids on particle migration to achieve more effective control. First, the forces and moments acting on the particles are analyzed; then, fluid dynamics, non-Newtonian fluid mechanics, extended DLVO (Derjaguin Landau Verwey Overbeek theory), surface tension, and friction are applied on the combined effects of particle migration. Then, we reasonably predict the influence of gas–liquid interface movement on particle migration in non-Newtonian fluids. The theoretical results show that the movement of the gas–liquid interface in non-Newtonian fluids will increase the separation force acting on the particles, which will lead to particle migration. Second, we carry out the particle migration experiment of moving bubbles in non-Newtonian fluid. Experiments show that when the solid–liquid two-phase flow is originally stable, particle migration occurs after the bubble movement is added. This phenomenon shows that the non-Newtonian fluid with bubble motion has stronger particle migration ability. Although there are some errors, the experimental results basically support the theoretical data.

Style APA, Harvard, Vancouver, ISO itp.

Long, Li. "Simulation analysis of bubble coalescence behavior characteristics in non-Newtonian fluids based on the phase field method." Journal of Physics: Conference Series 2707, no. 1 (2024): 012132. http://dx.doi.org/10.1088/1742-6596/2707/1/012132.

Pełny tekst źródła

Streszczenie:

Abstract Gas-liquid two-phase flow is widely used in various fields of chemical production because of its stability. The bubble coalescence behavior has a significant impact on the size, shape and movement of bubbles. These parameters are important parameters for affecting the interphase mass and heat transfer processes and equipment performance. This paper presents a simulation study of the bubble coalescence behavior of non-Newtonian fluids using the phase field method through simulation software. The relative location of bubbles were divided into three types: vertical, parallel and random; and also the distribution of bubbles can be divided into three cases: symmetric, left-skewed and right-skewed. This paper focuses on the influence of the arrangements of the bubbles on their coalescence behavior in non-Newtonian fluids. The results show that in non-Newtonian fluids, the relative distance of the bubbles and the flow characteristics of the fluid are both key factors in whether bubble coalescence can occur, and they exhibit different patterns of action when the bubbles are in different arrangements. Also bubbles show different patterns of motion in different distributions.

Style APA, Harvard, Vancouver, ISO itp.

Aquino, Andrea, Davide Picchi, and Pietro Poesio. "Modeling the motion of a Taylor bubble in a microchannel through a shear-thinning fluid." E3S Web of Conferences 312 (2021): 05006. http://dx.doi.org/10.1051/e3sconf/202131205006.

Pełny tekst źródła

Streszczenie:

Applications of multiphase flows in microchannels as chemical and biological reactors and cooling systems for microelectronic devices typically present liquid slugs alternated with bubbles of elongated shape, the Taylor bubbles. These occupy almost entirely the cross-section of the channel and present a hemispherical front and a liquid layer, the lubrication film, which separates the gas from the tube wall. The Taylor bubble perturbs the surrounding fluids activating many transport mechanisms in the proximity of the gas-liquid interface; therefore, the bubble motion significantly influences the heat and mass transfer rates. Although many works deeply investigate the bubble hydrodynamics in Newtonian fluids, the knowledge about the relation between bubble hydrodynamics and rheological properties is insufficient, and studies where the continuous phase exhibits a shear-thinning behavior are missing. Our numerical analysis tries to fill this gap by investigating the motion of a Taylor bubble in a non-Newtonian shear-thinning fluid, modeled by the Carreau viscosity model. First, we validate the results against the Newtonian case and a recent theory for shear-thinning fluids (Picchi et al., Journal of Fluid Mechanics, 2021, 918). Then, we investigate the bubble hydrodynamics far from the validity range of the current models. Finally, we study the scaling of the bubble velocity and lubrication film thickness, extending the current theory to shear-thinning fluids.

Style APA, Harvard, Vancouver, ISO itp.

Islam, Md Tariqul, P. Ganesan, and Ji Cheng. "A pair of bubbles’ rising dynamics in a xanthan gum solution: a CFD study." RSC Advances 5, no. 11 (2015): 7819–31. http://dx.doi.org/10.1039/c4ra15728a.

Pełny tekst źródła

Streszczenie:

The motion and interaction of a bubble pair in a non-Newtonian fluid are numerically simulated by a volume of fluid method. The effects of initial horizontal bubble interval, oblique alignment and fluid rheological properties on the pair of rising bubbles are evaluated.

Style APA, Harvard, Vancouver, ISO itp.

Almani, Sikandar, Muhammad Raheel Bawani, Ubedullah Ansari, Masroor Abro, Mashad Hussain, and Ali Abbas. "Design and fabrication of an indigenous confined bubble column: Investigation of single bubble ascent." Mehran University Research Journal of Engineering and Technology 44, no. 2 (2025): 25–34. https://doi.org/10.22581/muet1982.0053.

Pełny tekst źródła

Streszczenie:

In Chemical Process Industries (CPIs) like petrochemicals, biochemicals, and pharmaceuticals, gas-liquid interactions are crucial. Bubble columns are preferred for their low maintenance, absence of moving parts, and efficient mass transfer and mixing. Liquid phases in such systems often shift from Newtonian to non-Newtonian behavior, as seen in materials like molasses, cooking oil, and microalgae, affecting hydrodynamic parameters like gas holdup, mixing time and mass transfer. This study investigated single-bubble dynamics using an Indigenous confined bubble column (6 × 240 × 1140 mm³) in water (Newtonian) and CarboxyMethyl Cellulose (CMC) solutions (non-Newtonian) at 1 g/L, 2 g/L, and 3 g/L. The shadowgraphy technique measured bubble size, terminal velocity, Reynolds number, bubble count, and trajectory. In water, bubbles measured 1.48 mm, with sizes increasing to 1.87 mm and 2.08 mm in 2 g/L and 3 g/L CMC due to higher viscosity delaying detachment. Terminal velocity was 0.22 m/s in water, dropping to 0.11 m/s, 0.107 m/s, and 0.088 m/s in 1 g/L, 2 g/L, and 3 g/L CMC, respectively. Reynolds numbers declined sharply from 335.2 in water to 31.5, 7.9, and 3.5 in CMC solutions, reflecting viscosity's inverse effect. Bubble count increased from 7 per frame in water to 14, 15, and 17 in CMC solutions, as lower terminal velocity prolonged bubble presence. Trajectories were zigzag in water but remained rectilinear in CMC solutions across all concentrations. These findings highlight rheology's significant impact on bubble behavior, which will be essential for optimising process parameters in various CPIs.

Style APA, Harvard, Vancouver, ISO itp.

Truby, J. M., S. P. Mueller, E. W. Llewellin, and H. M. Mader. "The rheology of three-phase suspensions at low bubble capillary number." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471, no. 2173 (2015): 20140557. http://dx.doi.org/10.1098/rspa.2014.0557.

Pełny tekst źródła

Streszczenie:

We develop a model for the rheology of a three-phase suspension of bubbles and particles in a Newtonian liquid undergoing steady flow. We adopt an ‘effective-medium’ approach in which the bubbly liquid is treated as a continuous medium which suspends the particles. The resulting three-phase model combines separate two-phase models for bubble suspension rheology and particle suspension rheology, which are taken from the literature. The model is validated against new experimental data for three-phase suspensions of bubbles and spherical particles, collected in the low bubble capillary number regime. Good agreement is found across the experimental range of particle volume fraction ( 0 ≤ ϕ p ≲ 0.5 ) and bubble volume fraction ( 0 ≤ ϕ b ≲ 0.3 ). Consistent with model predictions, experimental results demonstrate that adding bubbles to a dilute particle suspension at low capillarity increases its viscosity, while adding bubbles to a concentrated particle suspension decreases its viscosity. The model accounts for particle anisometry and is easily extended to account for variable capillarity, but has not been experimentally validated for these cases.

Style APA, Harvard, Vancouver, ISO itp.

Zhao, Xinxin, Xiangzhen Yan, Hongwei Jiang, et al. "Simulation Analysis of Gas Bubble Formation and Escape in Non-Newtonian Drilling Fluids." Geofluids 2021 (April 9, 2021): 1–14. http://dx.doi.org/10.1155/2021/6680653.

Pełny tekst źródła

Streszczenie:

In this study, the formation and escape movements of a bubble injected in non-Newtonian drilling fluid through a pore were numerically simulated using a volume of fluid method. The pattern of a single bubble and the pressure and velocity fields of the surrounding liquid phase during the bubble formation were analyzed and compared with experimental results; based on the comparison, the formation and escape properties of the bubble were further studied. In particular, the effects of static shear force, consistency coefficient, and flow behavior index on the growth and escape time of the bubble were analyzed. The results show that, owing to the effect of velocity on the viscosity of a non-Newtonian drilling fluid, the escape time and volume of the bubble increase with an increase in static shear force, consistency coefficient, and flow behavior index. Among the three parameters, the flow behavior index has the greatest effect. This is because the shear disturbance of a bubble to its surrounding fluid during its growth and escape, caused by the shear thinning of a yield-power-law fluid, reduces the fluid viscosity. The shear thinning decreases, and the resistance to the bubble increases as the flow behavior index approaches 1, leading to larger bubble formation times and separation volumes. An empirical formula for predicting the equivalent radius of bubbles considering the liquid yield stress, inertial force, viscous force, and surface tension is established. The average error of predicting the equivalent radius of detached bubble is 0.80%, which can provide a reference for the better study of bubble migration and flow pattern in non-Newtonian fluid.

Style APA, Harvard, Vancouver, ISO itp.

Fakhari, Ahmad, and Célio Fernandes. "Single-Bubble Rising in Shear-Thinning and Elastoviscoplastic Fluids Using a Geometric Volume of Fluid Algorithm." Polymers 15, no. 16 (2023): 3437. http://dx.doi.org/10.3390/polym15163437.

Pełny tekst źródła

Streszczenie:

The motion of air bubbles within a liquid plays a crucial role in various aspects including heat transfer and material quality. In the context of non-Newtonian fluids, such as elastoviscoplastic fluids, the presence of air bubbles significantly influences the viscosity of the liquid. This study presents the development of an interface-capturing method for multiphase viscoelastic fluid flow simulations. The proposed algorithm utilizes a geometric volume of fluid (isoAdvector) approach and incorporates a reconstructed distance function (RDF) to determine interface curvature instead of relying on volume fraction gradients. Additionally, a piecewise linear interface construction (PLIC) scheme is employed in conjunction with the RDF-based interface reconstruction for improved accuracy and robustness. The validation of the multiphase viscoelastic PLIC-RDF isoAdvector (MVP-RIA) algorithm involved simulations of the buoyancy-driven rise of a bubble in fluids with varying degrees of rheological complexity. First, the newly developed algorithm was applied to investigate the buoyancy-driven rise of a bubble in a Newtonian fluid on an unbounded domain. The results show excellent agreement with experimental and theoretical findings, capturing the bubble shape and velocity accurately. Next, the algorithm was extended to simulate the buoyancy-driven rise of a bubble in a viscoelastic shear-thinning fluid described by the Giesekus constitutive model. As the influence of normal stress surpasses surface tension, the bubble shape undergoes a transition to a prolate or teardrop shape, often exhibiting a cusp at the bubble tail. This is in contrast to the spherical, ellipsoidal, or spherical-cap shapes observed in the first case study with a bubble in a Newtonian fluid. Lastly, the algorithm was employed to study the buoyancy-driven rise of a bubble in an unbounded elastoviscoplastic medium, modeled using the Saramito–Herschel–Bulkley constitutive equation. It was observed that in very small air bubbles within the elastoviscoplastic fluid, the dominance of elasticity and capillary forces restricts the degree of bubble deformation. As the bubble volume increases, lateral stretching becomes prominent, resulting in the emergence of two tails. Ultimately, a highly elongated bubble shape with sharper tails is observed. The results show that by applying the newly developed MVP-RIA algorithm, with a tangible coarser grid compared to the algebraic VOF method, an accurate solution is achieved. This will open doors to plenty of applications such as bubble columns in reactors, oil and gas mixtures, 3D printing, polymer processing, etc.

Style APA, Harvard, Vancouver, ISO itp.

Moreira, Ana I., Luís A. M. Rocha, João Carneiro, José D. P. Araújo, João B. L. M. Campos, and João M. Miranda. "Isolated Taylor Bubbles in Co-Current with Shear Thinning CMC Solutions in Microchannels—A Numerical Study." Processes 8, no. 2 (2020): 242. http://dx.doi.org/10.3390/pr8020242.

Pełny tekst źródła

Streszczenie:

Slug flow is a multiphase flow pattern characterized by the occurrence of long gas bubbles (Taylor bubbles) separated by liquid slugs. This multiphase flow regime is present in many and diversified natural and industrial processes, at macro and microscales, such as in eruption of volcanic magmas, oil recovery from pre-salt regions, micro heat exchangers, and small-sized refrigerating systems. Previous studies in the literature have been mostly focused on tubular gas bubbles flowing in Newtonian liquids. In this work, results from several numerical simulations of tubular gas bubbles flowing in a shear thinning liquid in microchannels are reported. To simulate the shear thinning behavior, carboxymethylcellulose (CMC) solutions with different concentrations were considered. The results are compared with data from bubbles flowing in Newtonian liquids in identical geometric and dynamic conditions. The numerical work was carried out in computational fluid dynamics (CFD) package Ansys Fluent (release 16.2.0) employing the volume of fluid (VOF) methodology to track the volume fraction of each phase and the continuum surface force (CSF) model to insert the surface tension effects. The flow patterns, the viscosity distribution in the liquid, the liquid film thickness between the bubble and the wall, and the bubbles shape are analyzed for a wide range of shear rates. In general, the flow patterns are similar to those in Newtonian liquids, but in the film, where a high viscosity region is observed, the thickness is smaller. Bubble velocities are smaller for the non-Newtonian cases.

Style APA, Harvard, Vancouver, ISO itp.

Hersey, Eric, Mauro Rodriguez, and Eric Johnsen. "Dynamics of an oscillating microbubble in a blood-like Carreau fluid." Journal of the Acoustical Society of America 153, no. 3 (2023): 1836–45. http://dx.doi.org/10.1121/10.0017342.

Pełny tekst źródła

Streszczenie:

A numerical model for cavitation in blood is developed based on the Keller–Miksis equation for spherical bubble dynamics with the Carreau model to represent the non-Newtonian behavior of blood. Three different pressure waveforms driving the bubble oscillations are considered: a single-cycle Gaussian waveform causing free growth and collapse, a sinusoidal waveform continuously driving the bubble, and a multi-cycle pulse relevant to contrast-enhanced ultrasound. Parameters in the Carreau model are fit to experimental measurements of blood viscosity. In the Carreau model, the relaxation time constant is 5–6 orders of magnitude larger than the Rayleigh collapse time. As a result, non-Newtonian effects do not significantly modify the bubble dynamics but do give rise to variations in the near-field stresses as non-Newtonian behavior is observed at distances 10–100 initial bubble radii away from the bubble wall. For sinusoidal forcing, a scaling relation is found for the maximum non-Newtonian length, as well as for the shear stress, which is 3 orders of magnitude larger than the maximum bubble radius.

Style APA, Harvard, Vancouver, ISO itp.

PILLAPAKKAM, SHRIRAM B., PUSHPENDRA SINGH, DENIS BLACKMORE, and NADINE AUBRY. "Transient and steady state of a rising bubble in a viscoelastic fluid." Journal of Fluid Mechanics 589 (October 8, 2007): 215–52. http://dx.doi.org/10.1017/s0022112007007628.

Pełny tekst źródła

Streszczenie:

A finite element code based on the level-set method is used to perform direct numerical simulations (DNS) of the transient and steady-state motion of bubbles rising in a viscoelastic liquid modelled by the Oldroyd-B constitutive equation. The role of the governing dimensionless parameters, the capillary number (Ca), the Deborah number (De) and the polymer concentration parameter c, in both the rising speed and the deformation of the bubbles is studied. Simulations show that there exists a critical bubble volume at which there is a sharp increase in the terminal velocity with increasing bubble volume, similar to the behaviour observed in experiments, and that the shape of both the bubble and its wake structure changes fundamentally at that critical volume value. The bubbles with volumes smaller than the critical volume are prolate shaped while those with volumes larger than the critical volume have cusp-like trailing ends. In the latter situation, we show that there is a net force in the upward direction because the surface tension no longer integrates to zero. In addition, the structure of the wake of a bubble with a volume smaller than the critical volume is similar to that of a bubble rising in a Newtonian fluid, whereas the wake structure of a bubble with a volume larger than the critical value is strikingly different. Specifically, in addition to the vortex ring located at the equator of the bubble similar to the one present for a Newtonian fluid, a vortex ring is also present in the wake of a larger bubble, with a circulation of opposite sign, thus corresponding to the formation of a negative wake. This not only coincides with the appearance of a cusp-like trailing end of the rising bubble but also propels the bubble, the direction of the fluid velocity behind the bubble being in the opposite direction to that of the bubble. These DNS results are in agreement with experiments.

Style APA, Harvard, Vancouver, ISO itp.

Araújo, J. D. P., J. M. Miranda, and J. B. L. M. Campos. "CFD Study of the Hydrodynamics of Slug Flow Systems: Interaction between Consecutive Taylor Bubbles." International Journal of Chemical Reactor Engineering 13, no. 4 (2015): 541–49. http://dx.doi.org/10.1515/ijcre-2014-0161.

Pełny tekst źródła

Streszczenie:

Abstract Slug flow is one of the most frequently occurring multiphase flow patterns in industrial processes. A deep knowledge of its fundamentals is necessary to accurately model not only the fluid flow but also reaction and heat and mass transfer in several operation units. A numerical study is reported on the dynamics of slug flow, under laminar regime, in vertical columns of stagnant and co-current Newtonian and non-Newtonian liquids (shear-thickening and shear-thinning). A CFD package (Ansys FLUENT) with the VOF methodology was applied to simulate the flow of individual and pairs of consecutive Taylor bubbles. The behaviour of the most relevant hydrodynamic features with the approach of the trailing bubble towards the leading one is addressed, with particular emphasis to the role of the liquid rheology and flow configuration. The main results presented are the velocity ratio curves between consecutive bubbles, the variation of the bubbles shape, and the axial velocity and viscosity fields in the surrounding liquid. This bubble-bubble interaction data can be a keystone to improve and complement continuous slug flow simulators used for very long columns.

Style APA, Harvard, Vancouver, ISO itp.

Mitrou, Stamatina, Simona Migliozzi, Luca Mazzei, and Panagiota Angeli. "On the linear viscoelastic behavior of semidilute polydisperse bubble suspensions in Newtonian media." Journal of Rheology 68, no. 4 (2024): 539–52. http://dx.doi.org/10.1122/8.0000745.

Pełny tekst źródła

Streszczenie:

In this work, we investigated the linear viscoelasticity of semidilute polydisperse bubble suspensions via small amplitude oscillatory shear (SAOS) tests performed in a rheo-optical setup. For all tested suspensions, the measured viscoelastic moduli (G′, G″) aligned with the theoretical predictions of the Jeffreys model for average dynamic capillary numbers (⟨Cd⟩) greater than unity. But at lower ⟨Cd⟩ values, experimental G′ values exceeded theoretical predictions. To investigate this, we considered the effects of suspension polydispersity and various SAOS measurement artifacts, including bubble rise, coalescence, and changes in suspension microstructure over time. Polydispersity could not cause the observed deviation, because the viscoelastic trends deviate from those of classic single-mode relaxation only for bimodal bubble size distributions with equal volume fractions of very small and very large bubbles; in any other case, the polydisperse suspension behaves as monodisperse with a bubble radius equal to the volume-weighted mean radius. Furthermore, bubble rise proved to play a minor role, while SAOS rheo-optical experiments revealed that bubble size and organization varied negligibly during our measurements. The G′ deviation at low ⟨Cd⟩ values was linked to bubble fluid dynamic interactions induced by the bubble spatial distribution. Image analysis showed that at low bubble volume fractions, stronger and prolonged preshearing reduces these interactions by increasing the average interbubble distance. But this effect is negligible in denser suspensions, which show similar G′ trends for any applied preshearing. Finally, a multimode Jeffreys model fitted to the experimental data showed that bubble interactions complicate the relaxation process, introducing multiple relaxation modes.

Style APA, Harvard, Vancouver, ISO itp.

Liu, Yaxin, Eric R. Upchurch, and Evren M. Ozbayoglu. "Experimental Study of Single Taylor Bubble Rising in Stagnant and Downward Flowing Non-Newtonian Fluids in Inclined Pipes." Energies 14, no. 3 (2021): 578. http://dx.doi.org/10.3390/en14030578.

Pełny tekst źródła

Streszczenie:

An experimental investigation of single Taylor bubbles rising in stagnant and downward flowing non-Newtonian fluids was carried out in an 80 ft long inclined pipe (4°, 15°, 30°, 45° from vertical) of 6 in. inner diameter. Water and four concentrations of bentonite–water mixtures were applied as the liquid phase, with Reynolds numbers in the range 118 < Re < 105,227 in countercurrent flow conditions. The velocity and length of Taylor bubbles were determined by differential pressure measurements. The experimental results indicate that for all fluids tested, the bubble velocity increases as the inclination angle increases, and decreases as liquid viscosity increases. The length of Taylor bubbles decreases as the downward flow liquid velocity and viscosity increase. The bubble velocity was found to be independent of the bubble length. A new drift velocity correlation that incorporates inclination angle and apparent viscosity was developed, which is applicable for non-Newtonian fluids with the Eötvös numbers (E0) ranging from 3212 to 3405 and apparent viscosity (μapp) ranging from 0.001 Pa∙s to 129 Pa∙s. The proposed correlation exhibits good performance for predicting drift velocity from both the present study (mean absolute relative difference is 0.0702) and a database of previous investigator’s results (mean absolute relative difference is 0.09614).

Style APA, Harvard, Vancouver, ISO itp.

Bräuer, Felix, Elias Trautner, Josef Hasslberger, Paolo Cifani, and Markus Klein. "Turbulent Bubble-Laden Channel Flow of Power-Law Fluids: A Direct Numerical Simulation Study." Fluids 6, no. 1 (2021): 40. http://dx.doi.org/10.3390/fluids6010040.

Pełny tekst źródła

Streszczenie:

The influence of non-Newtonian fluid behavior on the flow statistics of turbulent bubble-laden downflow in a vertical channel is investigated. A Direct Numerical Simulation (DNS) study is conducted for power-law fluids with power-law indexes of 0.7 (shear-thinning), 1 (Newtonian) and 1.3 (shear-thickening) in the liquid phase at a gas volume fraction of 6%. The flow is driven downward by a constant volumetric flow rate corresponding to a friction Reynolds number of Reτ≈127.3. The Eötvös number is varied between Eo=0.3125 and Eo=3.75 in order to investigate the influence of quasi-spherical as well as wobbling bubbles and thus the interplay of the bubble deformability with the power-law behavior of the liquid bulk. The resulting first- and second-order fluid statistics, i.e., the gas fraction, mean velocity and velocity fluctuation profiles across the channel, show clear trends in reply to varying power-law indexes. In addition, it was observed that the bubble oscillations increase with decreasing power-law index. In the channel core, the bubbles significantly increase the dissipation rate, which, in contrast to its behavior at the wall, shows similar orders of magnitude for all power-law indexes.

Style APA, Harvard, Vancouver, ISO itp.

Yoshida, Masanori, Hitoshi Igarashi, Kento Iwasaki, Sayaka Fuse, and Aya Togashi. "Evaluation of Viscosity of Non-Newtonian Liquid Foods with a Flow Tube Instrument." International Journal of Food Engineering 11, no. 6 (2015): 815–23. http://dx.doi.org/10.1515/ijfe-2015-0138.

Pełny tekst źródła

Streszczenie:

Abstract In a flow tube instrument modeled after a structurally simple and easy-to-use bubble viscometer, bubble ascent and liquid flow were examined to evaluate the physically defined viscosity of non-Newtonian liquid foods. For Newtonian and non-Newtonian test liquids, a dimensionless expression between the friction coefficient and Reynolds number, which was derived through analysis as an annular flow of liquid around bubble, indicated that the flow in the instrument was laminar. Prediction organized based on the empirical relation was advanced for evaluation of the non-Newtonian viscosity. The flow tube instrument was expected to be applicable to the conditions in drinking and eating, from a viewpoint of the characteristic shear rate ranging from 10 to 100 s−1.

Style APA, Harvard, Vancouver, ISO itp.

Wang, Tao, Jian Hua Zhang, Yi Zhang, and Xiu Hua Ren. "Optimization of Bubble Amount in Resin Mineral Composite Based Vacuum Pouring Procedure." Applied Mechanics and Materials 395-396 (September 2013): 60–63. http://dx.doi.org/10.4028/www.scientific.net/amm.395-396.60.

Pełny tekst źródła

Streszczenie:

With good vibration alleviating property, resin mineral composite has been used to produce main components of machine tools to satisfy the requirements of machining efficiency. Bubble in RMC is one of the key influences on compression strength, its amount and distribution determines the overall mechanical properties of the composite directly. In this article, bubble nucleation and free energy theory are used to explain the generation mechanism of bubbles by subdividing them into two parts, bubbles generated in granite and bubbles generated in resin. Mechanical model of single raised bubble in micro cylinder channel is established based on the flow characteristics of non-newtonian fluid. In order to validate the aforementioned assumptions, typical RMC samples are produced. Strength test and draining method are used to get their compression strength and bulk density. Experimental results show that sample with vacuum pouring process has smaller bubble amount and better compression strength performance, which is consistent with the mechanical model.

Style APA, Harvard, Vancouver, ISO itp.

Yao, Shun, Yichong Chen, Yijie Ling, Dongdong Hu, Zhenhao Xi, and Ling Zhao. "Analysis of Bubble Growth in Supercritical CO2 Extrusion Foaming Polyethylene Terephthalate Process Based on Dynamic Flow Simulation." Polymers 13, no. 16 (2021): 2799. http://dx.doi.org/10.3390/polym13162799.

Pełny tekst źródła

Streszczenie:

Bubble growth in the polymer extrusion foaming process occurs under a dynamic melt flow. For non-Newtonian fluids, this work successfully coupled the dynamic melt flow simulation with the bubble growth model to realize bubble growth predictions in an extrusion flow. The initial thermophysical properties and dynamic rheological property distribution at the cross section of the die exit were calculated based on the finite element method. It was found that dynamic rheological properties provided a necessary solution for predicting bubble growth during the supercritical CO2 polyethylene terephthalate (PET) extrusion foaming process. The introduction of initial melt stress could effectively inhibit the rapid growth of bubbles and reduce the stable size of bubbles. However, the initial melt stress was ignored in previous work involving bubble growth predictions because it was not available. The simulation results based on the above theoretical model were consistent with the evolution trends of cell morphology and agreed well with the actual experimental results.

Style APA, Harvard, Vancouver, ISO itp.

Mitrou, Stamatina, Simona Migliozzi, Panagiota Angeli, and Luca Mazzei. "Effect of polydispersity and bubble clustering on the steady shear viscosity of semidilute bubble suspensions in Newtonian media." Journal of Rheology 67, no. 3 (2023): 635–46. http://dx.doi.org/10.1122/8.0000585.

Pełny tekst źródła

Streszczenie:

In this work, we examine the steady shear rheology of semidilute polydisperse bubble suspensions to elucidate the role of polydispersity on the viscosity of these systems. We prove theoretically that the effect of polydispersity on suspension viscosity becomes apparent only if the bubble size distribution is bimodal, with very small and very large bubbles having similar volume fractions. In any other case, we can consider the polydisperse suspension as monodisperse, with the average bubble diameter equal to the De Brouckere mean diameter ([Formula: see text]). To confirm the theoretical results, we carried out steady shear rheological tests. Our measurements revealed an unexpected double power-law decay of the suspension relative viscosity at average capillary numbers between 0.01 and 1. To investigate this behavior further, we visualized the produced bubble suspensions under shear. The visualization experiments revealed that bubbles started forming clusters and threads at an average capillary number around 0.01, where we observed the first decay of viscosity. Clustering and alignment have been associated with shear-thinning behavior in particle suspensions. We believe that the same holds for bubble suspensions, where bubble clusters and threads align with the imposed shear flow, reducing the streamline distortions and, in turn, resulting in a decrease in the suspension viscosity. Consequently, we can attribute the first decay of the relative viscosity to the formation of bubble clusters and threads, proving that the novel shear-thinning behavior we observed is due to a combination of bubble clustering and deformation.

Style APA, Harvard, Vancouver, ISO itp.

Hariri, Amirhossein, Mohammad T. Shervani-Tabar, and Rezayat Parvizi. "Laser-Produced Cavitation Bubble Behavior in Newtonian and Non-Newtonian Liquid Inside a Rigid Cylinder: Numerical Study of Liquid Disc Microjet Impact Using OpenFOAM." Micromachines 14, no. 7 (2023): 1416. http://dx.doi.org/10.3390/mi14071416.

Pełny tekst źródła

Streszczenie:

This study employs OpenFOAM to analyze the behavior of a single laser-produced cavitation bubble in a Newtonian/non-Newtonian fluid inside a rigid cylinder. This research aimed to numerically calculate the impact of liquid disc microjet resulting from the growth and collapse of the laser-produced bubble to the cylinder wall to take advantage of the cavitation phenomenon in various industrial and medical applications, such as modeling how to remove calcification lesions in coronary arteries. In addition, by introducing the main study cases in which a single bubble with different initial conditions is produced by a laser in the center/off-center of a cylinder with different orientations relative to the horizon, filled with a stationary or moving Newtonian/Non-Newtonian liquid, the general behavior of the bubble in the stages of growth and collapse and the formation of liquid disk microjet and its impact is examined. The study demonstrates that the presence of initial velocity in water affects the amount of microjet impact proportional to the direction of gravity. Moreover, the relationship between the laser energy and the initial conditions of the bubble and the disk microjet impact on the cylinder wall is expressed.

Style APA, Harvard, Vancouver, ISO itp.

Jia, Zheng, Mingjun Pang, and Ruipeng Niu. "Numerical Investigation on Effect of Bubbles Arrangement and Volume Fraction on Apparent Viscosity of Bubbly Suspensions." Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) 16, no. 4 (2023): 285–304. http://dx.doi.org/10.2174/0124055204268474230922054143.

Pełny tekst źródła

Streszczenie:

Background:: Bubbly suspensions can be often run into in natural and industrial processes. The addition of bubbles with different sizes can lead to a significant change in the rheological properties of a matrix liquid. It is extremely significant to fully understand the rheological properties of bubbly suspensions for improving process efficiencies and optimizing productive processes. background: Bubbly suspensions can be often run into in natural and industrial processes. The addition of bubbles of different sizes can greatly change the rheological properties of matrix liquid. It is extremely significant to fully understand the rheological properties of bubbly suspensions for improving process efficiencies and optimizing productive processes. Objective:: The objective of this study is to explore qualitatively the physical law and internal mechanism of the apparent viscosity of suspensions formed by a Newtonian liquid containing different bubbles. Methods:: Based on the parallel plate model of shear flow, the volume of fluid method (VOF) was used to investigate the effect of bubble arrangement and volume fraction on the apparent viscosity of bubbly suspensions at low volume fractions. The piecewise linear interface calculation (PLIC) method was applied to reconstruct the interface based on the phase function. Results:: The present results show that the relative viscosity (ηr) of bubbly suspensions shows a nonlinear change with an increase in bubble volume fraction (ϕ). When the capillary number (Ca) is less than 0.6, ηr shows a nonlinear increase with an increase in ϕ (ηr increases from 1 to 1.03 with an increase in ϕ from 0 to 2.94% at Ca=0.1). However, Ca is greater than or equal to 0.6, ηr shows a nonlinear decrease with an increase in ϕ (ηr decreases from 1 to 0.92 with an increase in ϕ from 0 to 2.94% at Ca=2.5). Even if ϕ is the same, different arrangements of bubbles can lead to different magnitudes of apparent viscosity of bubbly suspensions Conclusion:: As ϕ increases, the region of low shear rate increases, which leads to a non−linear decrease in the relative viscosity. When ϕ is the same, the different arrangements of bubbles can lead to different effects on bubble dynamics and flow fields. This results in different viscous dissipation in bubbly suspensions. Thus, the apparent viscosity of bubbly suspensions is different. other: Nothing

Style APA, Harvard, Vancouver, ISO itp.

ALEXANDROU, A. N., V. M. ENTOV, S. S. KOLGANOV, and N. V. KOLGANOVA. "On bubble rising in a Hele–Shaw cell filled with a non-Newtonian fluid." European Journal of Applied Mathematics 15, no. 3 (2004): 315–27. http://dx.doi.org/10.1017/s0956792504005509.

Pełny tekst źródła

Streszczenie:

The problem of a bubble rising due to buoyancy in a Hele–Shaw cell filled with a viscous fluid is a classical free-boundary problem first posed and solved by Saffman & Taylor [11]. In fact, due to linearity of the flow equations the problem is reduced to that of a bubble transported by uniform fluid flow. Saffman and Taylor provided explicit expressions for the bubble shape. Steady propagation of bubbles and fingers in a Hele–Shaw cell filled with a nonlinearly-viscous fluid was studied by Alexandrou & Entov [1]. In Alexandrou & Entov [1], it was shown that for a nonlinearly viscous fluid the problem of a rising bubble cannot be reduced to that of a steadily transported bubble, and should be treated separately. This note presents a solution of the problem following the general framework suggested in Alexandrou & Entov [1]. The hodograph transform is used in combination with finite-difference and collocation techniques to solve the problem. Results are presented for the cases of a Bingham and power-law fluids.

Style APA, Harvard, Vancouver, ISO itp.

Vélez-Cordero, J. Rodrigo, Johanna Lantenet, Juan Hernández-Cordero, and Roberto Zenit. "Compact bubble clusters in Newtonian and non-Newtonian liquids." Physics of Fluids 26, no. 5 (2014): 053101. http://dx.doi.org/10.1063/1.4874630.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Favelukis, Moshe, and Ramon J. Albalak. "Bubble growth in viscous newtonian and non-newtonian liquids." Chemical Engineering Journal and the Biochemical Engineering Journal 63, no. 3 (1996): 149–55. http://dx.doi.org/10.1016/s0923-0467(96)03119-3.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Jiang, Xiao F., Chunying Zhu, and Huai Z. Li. "Bubble pinch-off in Newtonian and non-Newtonian fluids." Chemical Engineering Science 170 (October 2017): 98–104. http://dx.doi.org/10.1016/j.ces.2016.12.057.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Fan, Wenyuan, and Xiaohong Yin. "Bubble formation in shear-thinning fluids: Laser image measurement and a novel correlation for detached volume." Chemical Industry and Chemical Engineering Quarterly 23, no. 3 (2017): 301–9. http://dx.doi.org/10.2298/ciceq151019045f.

Pełny tekst źródła

Streszczenie:

A laser image system has been established to quantify the characteristics of growing bubbles in quiescent shear-thinning fluids. Bubble formation mechanism was investigated by comparing the evolutions of bubble instantaneous shape, volume and surface area in two shear-thinning liquids with those in Newtonian liquid. The effects of solution mass concentration, gas chamber volume and orifice diameter on bubble detachment volume are discussed. By dimensional analysis, a single bubble volume detached within a moderate gas flowrate range was developed as a function of Reynolds number ,Re, Weber number, We, and gas chamber number, Vc, based on the orifice diameter. The results reveal that the generated bubble presents a slim shape due to the shear-thinning effect of the fluid. Bubble detachment volume increases with the solution mass concentration, gas chamber volume and orifice diameter. The results predicted by the present correlation agree better with the experimental data than the previous ones within the range of this paper.

Style APA, Harvard, Vancouver, ISO itp.

Morshed, Munzarin, Muhammad Saad Khan, Mohammad Azizur Rahman, and Syed Imtiaz. "Flow Regime, Slug Frequency and Wavelet Analysis of Air/Newtonian and Air/non-Newtonian Two-Phase Flow." Applied Sciences 10, no. 9 (2020): 3272. http://dx.doi.org/10.3390/app10093272.

Pełny tekst źródła

Streszczenie:

This study focused on gas/Newtonian and gas/non-Newtonian two-phase horizontal fluid flow behavior by analyzing their flow regime identification and flow structural analysis on a horizontal flow loop apparatus. This involved the recognition of two-phase flow regimes for this flow loop and validation with existing flow maps in the literature. In addition, the study included flow pattern identification via wavelet analysis for gas/Newtonian and gas/non-Newtonian two-phase fluid flow in a horizontal flow loop apparatus. Furthermore, the study was extended to the detailed examination of slug frequency in the presence of air/Newtonian and air/non-Newtonian fluid flow, and the predicted slug frequency model was applied to the studied systems. The obtained results suggest that the flow regime maps and slug frequency analysis have a significant impact. The obtained pressure sensor results indicate that the experimental setup could not provide high-frequency and high-resolution data; nevertheless, wavelet decomposition and wavelet norm entropy were calculated. It offered recognizable flow characteristics for bubble, bubble-elongated bubble, and slug flow patterns. Therefore, this study can provide deep insight into intricate multiphase flow patterns, and the wavelet could potentially be applied for flow analysis in oil and gas pipelines.

Style APA, Harvard, Vancouver, ISO itp.

Allen, John, and Ronald A. Roy. "Bubble dynamics in non‐Newtonian fluids." Journal of the Acoustical Society of America 103, no. 5 (1998): 3013. http://dx.doi.org/10.1121/1.422486.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Muljani, Srie, Heru Setyawan, and Reva Edra Nugraha. "Bubble formation phenomenon on the absorber column for CO₂ absorption and to produce precipitated silica sodium carbonate." RSC Advances 13, no. 47 (2023): 33471–83. http://dx.doi.org/10.1039/d3ra05860c.

Pełny tekst źródła

Streszczenie:

CO2 absorption using sodium silicate aqueous solution in a bubble column has been studied. Sodium silicate aqueous solutions are classified as non-Newtonian fluids that can affect the bubble distribution.

Style APA, Harvard, Vancouver, ISO itp.

Shen, Zhongxiang, Ming Gao, Wuhan Dong, and Lixin Zhang. "Comparative experimental study on dynamic characteristics of bubble microlayers in small channel flow boiling and pool boiling." Journal of Physics: Conference Series 2280, no. 1 (2022): 012036. http://dx.doi.org/10.1088/1742-6596/2280/1/012036.

Pełny tekst źródła

Streszczenie:

Abstract The microlayer present at the bottom of the bubble plays a very important role in heat transfer during nucleation boiling. In this paper, the dynamic characteristics of microlayer at the bottom of boiling bubble in a small channel were studied by laser interferometry method and high speed camera, and the results were compared with pool boiling experiments. The results show that the bubbles have an obvious tendency to slip in the flow boiling. The microlayer interference fringe is deformed and no longer a complete Newtonian ring. By analyzing the thickness distribution of microlayer in different directions in flow boiling and the change of micro-contact angle in the flow direction, it was found that the micro-contact angle in the flow direction became larger with the growth of bubbles.

Style APA, Harvard, Vancouver, ISO itp.

Pełny tekst źródła

Streszczenie:

Style APA, Harvard, Vancouver, ISO itp.

Li, H. Z., Y. Mouline, L. Choplin, and N. Midoux. "Chaotic bubble coalescence in non-Newtonian fluids." International Journal of Multiphase Flow 23, no. 4 (1997): 713–23. http://dx.doi.org/10.1016/s0301-9322(97)00004-9.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Brujan, Emil-Alexandru. "Cavitation bubble dynamics in non-Newtonian fluids." Polymer Engineering & Science 49, no. 3 (2008): 419–31. http://dx.doi.org/10.1002/pen.21292.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Rodrigue, Denis, Daniel De Kee, and C. F. Chan Man Fong. "Bubble drag in contaminated non-newtonian solutions." Canadian Journal of Chemical Engineering 75, no. 4 (1997): 794–96. http://dx.doi.org/10.1002/cjce.5450750418.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Chen, Zai Liang, and Tian Qi Huang. "Mathematical Model of Bubble Dissolution Process in Polymer Melt." Advanced Materials Research 154-155 (October 2010): 1251–54. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.1251.

Pełny tekst źródła

Streszczenie:

In this paper, a mathematical model of the process of bubble dissolution is built .In this model , the DeWitt constitutive equation reflect is used, it can reflect the performance of non-Newtonian fluid and calculation is relatively simple. The model was solved by finite difference method, and the results show that the initial bubble radius and the outside pressure is the main factor affecting the bubble dissolution.

Style APA, Harvard, Vancouver, ISO itp.

Kawase, Y., and M. Moo-Young. "Liquid phase mixing in bubble columns with Newtonian and non-Newtonian fluids." Chemical Engineering Science 41, no. 8 (1986): 1969–77. http://dx.doi.org/10.1016/0009-2509(86)87113-5.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Fan, Wen Yuan, and Xiao Hong Yin. "Fractal Approach to Bubble Rising Dynamics in Non-Newtonian Fluids." Advanced Materials Research 889-890 (February 2014): 559–62. http://dx.doi.org/10.4028/www.scientific.net/amr.889-890.559.

Pełny tekst źródła

Streszczenie:

The Laser Doppler anemometry was employed to determine quantitatively the liquid velocity induced by the successive rising of single bubble in non-Newtonian carboxymethylcellulose (CMC) aqueous solutions under various experimental conditions of mass concentration solutions, measures heights and gas flow rate. The features of liquid motion in the region of bubble rising channel were investigated by analysis the liquid velocity pulsation using fractal theory. The results show that the liquid motion in the channel zone of bubble rise has a special feature of double fraction, and shows strong positive persistence characteristics for a small delay, but the positive persistence characteristics begins to reduce obviously with the increase of the delay, and even presents the anti-persistence for some measured points.

Style APA, Harvard, Vancouver, ISO itp.

HAQUE, M. W., K. D. P. NIGAM, K. VISWANATHAN, and J. B. JOSHI. "STUDIES ON BUBBLE RISE VELOCITY IN BUBBLE COLUMNS EMPLOYING NON-NEWTONIAN SOLUTIONS." Chemical Engineering Communications 73, no. 1 (1988): 31–42. http://dx.doi.org/10.1080/00986448808940431.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

ALEXANDROU, ANDREAS N., and VLADIMIR ENTOV. "On the steady-state advancement of fingers and bubbles in a Hele–Shaw cell filled by a non-Newtonian fluid." European Journal of Applied Mathematics 8, no. 1 (1997): 73–87. http://dx.doi.org/10.1017/s0956792596002963.

Pełny tekst źródła

Streszczenie:

The problem of steady-state propagation of a finger or a bubble of inviscid fluid through a Hele–Shaw cell filled by a viscous non-Newtonian, including visco-plastic (Bingham) fluid is addressed. Only flows symmetric relative to the cell axis are considered. It is shown that, using a hodograph transform, this non-linear free boundary problem can be reduced to the solution of an elliptic system of linear partial differential equations in a fixed domain with part of the boundary being curvilinear. The resulting boundary-value problem is solved numerically using the Finite Element Method. Finger shapes are calculated, and the approach is verified for one-parameter family of solutions which correspond to the well-known Saffman–Taylor solutions for the case of a Hele–Shaw cell filled by a Newtonian fluid. Results are also shown for fingers with non-Newtonian fluids. In the case of a cell filled by visco-plastic (Bingham) fluid, it is shown that stagnant zones propagate with the finger, and that the rear part of the finger has constant width. The same approach is applied to finding a two-parametric family of solutions for steady propagating bubbles. Results are shown for bubbles in Hele–Shaw cell filled by power-law and Bingham fluids.

Style APA, Harvard, Vancouver, ISO itp.

TSAMOPOULOS, J., Y. DIMAKOPOULOS, N. CHATZIDAI, G. KARAPETSAS, and M. PAVLIDIS. "Steady bubble rise and deformation in Newtonian and viscoplastic fluids and conditions for bubble entrapment." Journal of Fluid Mechanics 601 (April 25, 2008): 123–64. http://dx.doi.org/10.1017/s0022112008000517.

Pełny tekst źródła

Streszczenie:

We examine the buoyancy-driven rise of a bubble in a Newtonian or a viscoplastic fluid assuming axial symmetry and steady flow. Bubble pressure and rise velocity are determined, respectively, by requiring that its volume remains constant and its centre of mass remains fixed at the centre of the coordinate system. The continuous constitutive model suggested by Papanastasiou is used to describe the viscoplastic behaviour of the material. The flow equations are solved numerically using the mixed finite-element/Galerkin method. The nodal points of the computational mesh are determined by solving a set of elliptic differential equations to follow the often large deformations of the bubble surface. The accuracy of solutions is ascertained by mesh refinement and predictions are in very good agreement with previous experimental and theoretical results for Newtonian fluids. We determine the bubble shape and velocity and the shape of the yield surfaces for a wide range of material properties, expressed in terms of the Bingham Bn=$\tau_y^{\ast}/\rho^{\ast}g^{\ast} R_b^{\ast}$ Bond Bo =$\rho^{\ast}g^{\ast} R_b^{\ast 2}/\gamma^{\ast}$ and Archimedes Ar=$\rho^{\ast2}g^{\ast} R_b^{\ast3}/\mu_o^{\ast2}$ numbers, where ρ* is the density, μ*o the viscosity, γ* the surface tension and τ*y the yield stress of the material, g* the gravitational acceleration and R*b the radius of a spherical bubble of the same volume. If the fluid is viscoplastic, the material will not be deforming outside a finite region around the bubble and, under certain conditions, it will not be deforming either behind it or around its equatorial plane in contact with the bubble. As Bn increases, the yield surfaces at the bubble equatorial plane and away from the bubble merge and the bubble becomes entrapped. When Bo is small and the bubble cannot deform from the spherical shape the critical Bn is 0.143, i.e. it is a factor of 3/2 higher than the critical Bn for the entrapment of a solid sphere in a Bingham fluid, in direct correspondence with the 3/2 higher terminal velocity of a bubble over that of a sphere under the same buoyancy force in Stokes flow. As Bo increases allowing the bubble to squeeze through the material more easily, the critical Bingham number increases as well, but eventually it reaches an asymptotic value. Ar affects the critical Bn value much less.

Style APA, Harvard, Vancouver, ISO itp.

Clark, Nigel N., Rory L. C. Flemmer, and Jan W. Van Egmond. "Non-newtonian two-phase circulation in bubble columns." Canadian Journal of Chemical Engineering 67, no. 5 (1989): 862–65. http://dx.doi.org/10.1002/cjce.5450670520.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Frank, Xavier, Huai Z. Li, Denis Funfschilling, Florence Burdin, and Youguang Ma. "Bubble Motion in Non-Newtonian Fluids and Suspensions." Canadian Journal of Chemical Engineering 81, no. 3-4 (2008): 483–90. http://dx.doi.org/10.1002/cjce.5450810321.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Kumar Jana, Sumit, and Sudip Kumar Das. "TAPERED BUBBLE COLUMN USING PSEUDOPLASTIC NON-NEWTONIAN LIQUIDS – EMPIRICAL CORRELATION FOR PRESSURE DROP." Chemistry & Chemical Technology 11, no. 3 (2017): 327–32. http://dx.doi.org/10.23939/chcht11.03.327.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Yamamoto, Takehiro, Takanori Suga, Kiyoji Nakamura, and Noriyasu Mori. "The Gas Penetration Through Viscoelastic Fluids With Shear-Thinning Viscosity in a Tube." Journal of Fluids Engineering 126, no. 2 (2004): 148–52. http://dx.doi.org/10.1115/1.1669402.

Pełny tekst źródła

Streszczenie:

The penetration of a long gas bubble through a viscoelastic fluid in a tube was studied. Experiments were carried out for two Newtonian and five polymeric solutions to investigate the relation between the coating film thickness and rheological properties of the test fluids. The polymeric solutions are viscoelastic fluids having shear-thinning viscosity. A bubble of air was injected into a tube filled with a test fluid to form hydrodynamic coating on a tube wall. The film thickness was evaluated by hydrodynamic fractional coverage m. The fractional coverage was characterized using the capillary number Ca and the Weissenberg number Wi. For viscoelastic fluids, Ca and Wi were evaluated considering the shear-thinning viscosity. Two kinds of representative shear rate were used for the evaluation of Ca and Wi. The dependence of m on Ca in viscoelastic fluids was different from that of the Newtonian case. The film was thinner than that of the Newtonian case at the same Ca when Wi was small, i.e. the viscous property was dominant. The shear-thinning viscosity had a role to make the film thin. On the other hand, the film tended to be thicker than the corresponding Newtonian results at large Wi because of normal stress effect.

Style APA, Harvard, Vancouver, ISO itp.

Kwak, Ho-Young. "Entropy Generation Due to the Heat Transfer for Evolving Spherical Objects." Entropy 20, no. 8 (2018): 562. http://dx.doi.org/10.3390/e20080562.

Pełny tekst źródła

Streszczenie:

Heat transfer accompanying entropy generation for the evolving mini and microbubbles in solution is discussed based on the explicit solutions for the hydrodynamic equations related to the bubble motion. Even though the pressure difference between the gas inside the bubble and liquid outside the bubble is a major driving force for bubble evolution, the heat transfer by conduction at the bubble-liquid interface affects the delicate evolution of the bubble, especially for sonoluminescing the gas bubble in sulfuric acid solution. On the other hand, our explicit solutions for the continuity, Euler equation, and Newtonian gravitational equation reveal that supernovae evolve by the gravitational force radiating heat in space during the expanding or collapsing phase. In this article, how the entropy generation due to heat transfer affects the bubble motion delicately and how heat transfer is generated by gravitational energy and evolving speed for the supernovae will be discussed. The heat transfer experienced by the bubble and supernovae during their evolution produces a positive entropy generation rate.

Style APA, Harvard, Vancouver, ISO itp.

Oferujemy zniżki na wszystkie plany premium dla autorów, których prace zostały uwzględnione w tematycznych zestawieniach literatury. Skontaktuj się z nami, aby uzyskać unikalny kod promocyjny!