Article
Mechanics
Vatsal Sanjay, Detlef Lohse, Maziyar Jalaal
Summary: In this study, the phenomenon of a rising bubble reaching the liquid-air interface in a yield-stress fluid was numerically investigated. Viscoplasticity was found to play a significant role in controlling the fate of capillary waves and their interaction at the bottom of the cavity, with the free surface converging to a non-flat equilibrium shape once the driving stresses fell below the yield stress. The dynamics and energy budgets of the flow were discussed, leading to the establishment of a regime map with four main regimes exhibiting different characteristic behaviors.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Fluids & Plasmas
Alexander A. Doinikov, Jonas Fankhauser, Juerg Dual
Summary: An analytical theory is developed to study acoustic streaming induced by an axisymmetric acoustic wave field around a solid spherical particle in a compressible viscoelastic fluid. The study shows that increasing polymer viscosity decreases streaming velocity magnitude, while increasing the elasticity of the polymer solution leads to an increase in streaming velocity magnitude as long as the relaxation time remains relatively small. Changes in polymer viscosity and relaxation time can alter the pattern of streamlines.
Article
Physics, Fluids & Plasmas
A. Kordalis, D. Pema, S. Androulakis, Y. Dimakopoulos, J. Tsamopoulos
Summary: This study investigates the buoyancy-driven rise and interaction between two coaxial bubbles in an elastoviscoplastic material. The development of a shear stress bridge between the bubbles decreases drag force on the trailing bubble, initiating their approach. The material's solidlike behavior makes it softer for the trailing bubble. Normal stresses primarily extend the bubbles, but the leading bubble eventually adopts a less favorable shape that slows it down. Geometric characteristics and material properties also affect the approach time.
PHYSICAL REVIEW FLUIDS
(2023)
Review
Chemistry, Physical
Dominique Langevin
Summary: This review focuses on the movement of bubbles and drops in viscoelastic materials, addressing the differences from Newtonian fluids. It covers cases of motion in quiescent fluids, small bubbles and drops, as well as recent advances in microrheology. The discussion also includes the motion of larger drops and bubbles in yield stress fluids, as well as recent developments in understanding the rheological properties of composite systems.
CURRENT OPINION IN COLLOID & INTERFACE SCIENCE
(2022)
Article
Mechanics
Ming-Kang Li, Shi-Ping Wang, Shuai Zhang, Hemant Sagar
Summary: This study experimentally investigates the complex interaction between underwater explosion (UNDEX) bubbles and a free surface. The dependence of the associated physics on the dimensionless detonation depth is revealed. Four typical bubble behavior patterns are identified and a critical value is found for ignoring the effects of the free surface on UNDEX bubbles. Good agreements are obtained with a unified theory for bubble dynamics. The dependence of pressure signals on the detonation depth is also investigated.
Article
Physics, Fluids & Plasmas
Daniel T. Paterson, Tom S. Eaves, Duncan R. Hewitt, Neil J. Balmforth, D. Mark Martinez
Summary: In this study, a theoretical and experimental investigation was conducted on the one-dimensional compression of a networked suspension. The focus was on relatively rapid compression, and an elastoviscoplastic constitutive relation was included to improve the accuracy of the model. The experimental results were in good agreement with the model predictions, demonstrating a significant improvement in predicting the observed spatial compaction behavior.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Applied
Nehal Dash, Ganesh Tamadapu
Summary: This study presents an interesting revamp to the interface energy model for gas-filled encapsulated bubbles in a viscous fluid, by using the Gent hyperelastic material model and the upper-convected Maxwell constitutive relations. The effects of the newly introduced interface energy model and material parameters on the radial dynamics of the bubble are investigated through numerical simulations. The study highlights the nonlinear behavior and the influence of the viscoelastic shell material on the behavior of the bubble.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Mechanics
Wenjun Yuan, Mengqi Zhang, Boo Cheong Khoo, Nhan Phan-Thien
Summary: This paper investigates the inline rise of a pair of three-dimensional air bubbles in a viscoelastic liquid using direct numerical simulations. The study reveals the interaction patterns, coalescence, and separation tendencies of bubble pairs, as well as the impact of fluid elasticity on their behavior. The findings highlight the importance of long-range repulsion and short-range attraction in bubble pair interactions in viscoelastic fluids.
Article
Mechanics
Alie Abbasi Yazdi, Gaetano D'Avino
Summary: This study investigates the sedimentation behavior of a spherical particle in an elastoviscoplastic fluid near a flat wall through direct numerical simulations. The governing equations are solved using the finite element method with an Arbitrary Lagrangian-Eulerian formulation. The fluid is modeled using the modified Giesekus constitutive equation proposed by Saramito (2007). The results show that the presence of yield stress reduces the settling velocity and reverses the migration direction of the particle compared to the purely viscoelastic case. The effect of the wall on the yielded and unyielded regions around the particle is also examined. The reversed particle migration is attributed to the different shear rate distribution caused by the presence of the yielded region.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Chemistry, Analytical
Georgia Kontaxi, Yorgos G. Stergiou, Aikaterini A. Mouza
Summary: This study compares the characteristics of bubbles formed in non-Newtonian and Newtonian fluids, finding that the final diameter of the bubbles is influenced by the gas flow rate and liquid phase viscosity. Simulation results indicate that high shear rates around bubbles in non-Newtonian fluids lead to the viscosity approaching its asymptotic value.
Article
Physics, Multidisciplinary
Mohamed S. Abdelgawad, Ianto Cannon, Marco E. Rosti
Summary: Non-Newtonian fluids with interconnected elastic, viscous, and plastic properties are investigated through numerical simulations. The study focuses on turbulence in elastoviscoplastic fluids at high Reynolds number, particularly the effect of plasticity. The results show that increasing fluid plasticity reduces the active scales in the energy spectrum and introduces a new scaling range. Intermittency and enhanced extreme events are observed, driven by the non-Newtonian dissipation rate.
Article
Chemistry, Physical
Valerio Vitali, Giovanni Nava, Andrea Corno, Melissa Pezzotti, Francesca Bragheri, Petra Paie, Roberto Osellame, Marco Aldo Ortenzi, Ilaria Cristiani, Paolo Minzioni, Tommaso Bellini, Giuliano Zanchetta
Summary: The study investigates the transition of material flow characteristics at the microscale using an optofluidic microrheometer. Creep experiments on a model soft material revealed the yield stress values, and the plastic rearrangements of the surrounding material were traced using small passive tracers.
Article
Mechanics
A. Pourzahedi, M. Zare, I. A. Frigaard
Summary: Bubbles rising steadily in Carbopol often have an inverted teardrop shape with a pointed tail, which may be caused by viscoelasticity or fluid memory effects. Even after eliminating all possibilities of memory effects, the pointed tail still exists in steady bubble propagation. This suggests that the tail shape results from a combination of rheology and steady fluid deformation around the rising bubble.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2021)
Article
Astronomy & Astrophysics
Jose F. Nieves, Sarira Sahu
Summary: In this study, we investigate the calculation of thermal self-energy of a neutrino propagating in a medium composed of fermions and scalars interacting via a Yukawa-type coupling. By effectively treating singularities and considering background conditions, we obtained precise formulas for damping terms that depend on the distributions of background particles.
Article
Mechanics
JingTing Liu, ShanHao Cong, YongXing Song, DaZhuan Wu, SongYing Chen
Summary: This study developed a three-dimensional imaging system to examine the relationship between the flow patterns and acoustic characteristics of asymmetric bubbles formed in five nozzles. The results showed that the morphology of the bubbles became complex with increasing aspect ratio of the nozzle exit, and the asymmetry of the bubbles had a significant impact on the sound pressure.
Article
Physics, Multidisciplinary
Marco De Corato, Xavier Arque, Tania Patino, Marino Arroyoe, Samuel Sanchez, Ignacio Pagonabarraga
PHYSICAL REVIEW LETTERS
(2020)
Article
Mechanics
S. Saha, B. Saint-Michel, V Leynes, B. P. Binks, V Garbin
Review
Chemistry, Physical
Brice Saint-Michel, Valeria Garbin
CURRENT OPINION IN COLLOID & INTERFACE SCIENCE
(2020)
Article
Physics, Fluids & Plasmas
Marco De Corato, Ignacio Pagonabarraga, Loai K. E. A. Abdelmohsen, Samuel Sanchez, Marino Arroyo
PHYSICAL REVIEW FLUIDS
(2020)
Article
Robotics
Maria Guix, Rafael Mestre, Tania Patino, Marco De Corato, Judith Fuentes, Giulia Zarpellon, Samuel Sanchez
Summary: Bioinspired hybrid soft robots, which combine living and synthetic components, utilize unique characteristics not found in artificial materials, such as adaptability and response to external stimuli. By optimizing 3D-printed skeleton designs and electrically activating muscle tissue, these robots are able to achieve both swimming and gliding motion mechanisms.
Article
Chemistry, Multidisciplinary
Saikat Saha, Francis Pagaud, Bernard P. Binks, Valeria Garbin
Summary: Oil foams stabilized by crystallizing agents have excellent stability and potential applications in consumer products. The behavior of the interfacial layer at different time scales plays a crucial role in product shelf life and processing conditions. Experimental investigation reveals that the dynamics of deformation significantly affect the fate of the interfacial layer.
Article
Chemistry, Physical
Brice Saint-Michel, George Petekidis, Valeria Garbin
Summary: The dynamics of a deformable inclusion, such as a bubble, can be used to locally tune the microstructure of a colloidal gel. Bubble dissolution leads to the formation of a solvent pocket, while ultrasound-induced bubble oscillations rearrange the gel particles into a microstructure with increased local ordering.
Article
Mechanics
Marco De Corato, Daniele Tammaro, Pier Luca Maffettone, Norberto Fueyo
Summary: In this study, we investigate the retraction of a circular thin film coated with insoluble surfactants after being punctured. Our simulations show that the presence of surfactants slows down the retraction rate and introduces oscillations. As the surface elasticity increases, the film thickness perturbations spread over a larger area. Additionally, the surface perturbations travel faster than the retracting edge of the film at a speed proportional to the Gibbs modulus, approaching the behavior of an incompressible two-dimensional solid for large Gibbs modulus values.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Chemistry, Physical
Marco De Corato, Ignacio Pagonabarraga
Summary: This paper investigates the self-propulsion mechanism of chemically active colloids and their coupling relationship with chemical reactions and momentum transport. By studying Onsager reciprocal relations, it is found that if a chemical reaction drives the motion of the colloid, an external force generates a reaction rate. The validity of reciprocal relations is verified through numerical simulations, and the key role of solute advection in maintaining the symmetry of the Onsager matrix is highlighted. Furthermore, it is discovered that Onsager reciprocal relations break down under nonequilibrium steady states, which has implications for the thermal fluctuations of active colloids used in experiments.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Mechanics
Marco De Corato, Marino Arroyo
Summary: Chemically responsive polymers can respond to local variations in the chemical composition of a solution, leading to changes in their conformation and rheological properties. In this paper, a theory is developed to describe the flow of a mixture of solute and chemically responsive polymers, revealing novel couplings between the distribution of polymers and solutes.
JOURNAL OF RHEOLOGY
(2022)
Article
Physics, Multidisciplinary
Gaspard Junot, Marco De Corato, Pietro Tierno
Summary: We observe the emergence of large zigzag bands in a population of actuated magnetic rotors, which behave as active shakers. By combining experimental analysis with simulations, we show that the special flow field created by the shakers is the key ingredient for the observed spatiotemporal pattern.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Yanyan Liu, Mingjun Xu, Luis M. Portela, Valeria Garbin
Summary: Emulsions stabilized by nanoparticles, known as Pickering emulsions, show remarkable stability and have various applications. The layer of nanoparticles at the interface of Pickering droplets acts as a semi-permeable barrier, affecting the release rate of encapsulates and the interfacial transfer of reactants. However, our understanding of diffusion in multiphase systems with particle-laden interfaces is limited.
Review
Geosciences, Multidisciplinary
Berengere Dubrulle, Francois Daviaud, Davide Faranda, Louis Marie, Brice Saint-Michel
Summary: This article explores the scientific admissibility of climate projections and predictions, focusing on transitions between metastable states in atmospheric and oceanic circulations. By examining climate models' ability to replicate spontaneous or forced transitions in weather patterns, the study draws an analogy to laboratory-scale turbulent flows. Factors such as the nature of transitions, degrees of freedom, and the role of fluctuations are investigated, emphasizing the importance of accurately capturing small-scale fluctuations.
NONLINEAR PROCESSES IN GEOPHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Marco De Corato, Ignacio Pagonabarraga, Giovanniantonio Natale
Summary: The transition of polar active particles from polar to chiral symmetry is characterized by the emergence of active rotation and circular trajectories, driven by the advection of a solute that interacts differently with the two portions of the particle surface through a supercritical pitchfork bifurcation.