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
Multidisciplinary Sciences
Yujie Jiang, Ryohei Seto
Summary: Using simulations, the authors identify the interplay between two lengthscales that generically controls gelation in composite gels. Composite gels, which consist of gel and non-sticky inclusions, are more commonly encountered in reality. Numerical simulations show that the non-sticky particles confine gelation in terms of an effective volume fraction and introduce another competing lengthscale. The ratio of these two lengthscales controls the effects in colloidal composites.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Claudia Ferreiro-Cordova, Giuseppe Foffi, Olivier Pitois, Chiara Guidolin, Maxime Schneider, Anniina Salonen
Summary: The elastic properties of a soft matter material can be greatly affected by the presence of solid inclusions. This is due to the interactions between the gel backbone and the inclusions, leading to non-trivial changes in the elastic properties. Experimental studies on emulsions confirm the trends observed in simulations.
Article
Mechanics
Miguel E. Villalba, Masoud Daneshi, Emad Chaparian, D. Mark Martinez
Summary: This article presents an experimental and computational investigation of the internal flow of elastoviscoplastic fluids over non-smooth topologies. In the first study, the creeping flow of a Carbopol gel over a cavity embedded in a thin slot is visualized using optical coherence tomography (OCT) and confocal microscopy. The size and shape of the plug are measured as a function of Bingham and Weissenberg numbers. The second study involves numerical simulations using an adaptive finite element method based on an augmented Lagrangian scheme, where the asymmetry in the plug shape is quantified and presented as a function of the product of the Weissenberg and Bingham numbers.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2023)
Article
Mechanics
Daulet Izbassarov, Marco E. Rosti, Luca Brandt, Outi Tammisola
Summary: Direct numerical simulations investigate the impact of finite Weissenberg numbers up to Wi = 16 on laminar and turbulent channel flows of an elastoviscoplastic (EVP) fluid at a fixed bulk Reynolds number of 2800. The study reveals that drag decreases with both Bingham and Weissenberg numbers in turbulent flow until a transition to laminar flow occurs at high elastic and yield stresses. Furthermore, it is observed that plasticity affects both low- and high-speed streaks equally, attenuating turbulent dissipation and fragmentation of turbulent structures.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Anthony Man, Mohammad Jadidi, Amir Keshmiri, Hujun Yin, Yasser Mahmoudi
Summary: This paper introduces a novel zonal machine learning approach for Reynolds-averaged Navier-Stokes turbulence modeling based on the divide-and-conquer technique. The approach involves training and testing ML models in different flow physics regions called zones. The results show that the zonal models outperform the non-zonal models in predicting the Reynolds stress anisotropy and turbulent kinetic energy.
Article
Mechanics
Kunpeng Long, Olivier Coutier-Delgosha, Annie-Claude Bayeul-Laine
Summary: The paper focuses on the three-dimensional effects in a cavitating flow in a venturi-type profile. Experimental measurements based on 2D3C stereoscopic particle image velocimetry are conducted to obtain the three components of the velocity field in multiple vertical planes. The study reveals the presence of significant flow velocities in the third direction, attributed to differences in boundary conditions and intrinsic three-dimensional mechanisms inside the cavitation area.
Article
Biotechnology & Applied Microbiology
Giuseppe C. A. Caridi, Elena Torta, Valentina Mazzi, Claudio Chiastra, Alberto L. L. Audenino, Umberto Morbiducci, Diego Gallo
Summary: This study presents an experimental set-up for characterizing the fluid dynamics in healthy and stenosed coronary arteries. The proposed smart-PIV approach, using a smartphone camera and low-power laser, provides both qualitative flow visualizations and quantitative results. Comparisons with conventional PIV measurements show good agreement, making smart-PIV a promising and low-cost methodology for cardiovascular flow characterization.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
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
Chemistry, Physical
P. Moschopoulos, E. Kouni, K. Psaraki, Y. Dimakopoulos, J. Tsamopoulos
Summary: This study investigates the stretching dynamics of a yield stress material with both elastic and viscoplastic behavior. The material forms a cylindrical liquid bridge initially and then a neck when subjected to stretching between coaxial disks. Theoretical analysis shows that an elongated thin neck is formed due to elasticity, connecting the upper and lower parts of the bridge. The findings suggest that the consideration of elasticity affects the pinching times and filament length in filament stretching procedures of yield stress materials.
Article
Polymer Science
Vladimir Shelukhin
Summary: The new mathematical model developed for rotational sedimentation of particles in a concentric-cylinder Couette geometry shows good agreement with known measurement data, validating its accuracy. Sedimentation is proven to occur due to particles' rotation and rotational diffusion according to the proposed theory.
Article
Mechanics
Chiya Savari, Mostafa Barigou
Summary: A new experimental-theoretical framework has been developed to investigate turbulence and turbulence modulation in a two-phase multicomponent particle-liquid flow in a mechanically agitated vessel. The study reveals that particle size, impeller pumping mode, and particle size distribution mode have significant impacts on liquid turbulence, with large particles enhancing liquid turbulence.
Article
Thermodynamics
Edgar M. Ofuchi, Henrique Stel, Ernesto Mancilla, Rigoberto E. M. Morales
Summary: This study aims to investigate the flow field in a centrifugal rotor using two-dimensional Particle Image Velocimetry (PIV). The analysis of flow at different planes under various operating conditions revealed that the flow in the centrifugal rotor behaves according to kinematic similarity, even at part-load operation. Additionally, it was observed that the flow in the rotor channels can be considered periodic at the best efficiency point flow rate and under part-load conditions.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Mechanics
I. K. Karathanassis, M. Heidari-Koochi, Q. Zhang, J. Hwang, P. Koukouvinis, J. Wang, M. Gavaises
Summary: High-flux synchrotron radiation was utilized for real-time characterization of cavitation regions, using x-ray phase-contrast and absorption imaging to capture radiographs with sharp refractive index gradients and correlation with projected vapor thickness. A combination of the two methods accurately quantifies vapor content in complex nozzle flow.
Article
Engineering, Aerospace
Ruijie Bai, Jinping Li, Fanzhi Zeng, Chao Yan
Summary: Accurate prediction of flow separation is crucial for aerospace design, flight accident avoidance, and the development of fluid mechanics. However, existing Reynolds-averaged Navier-Stokes methods face challenges in accurately predicting separation due to its complex nature and unclear underlying mechanism. This study analyzes the reasons for the inaccurate predictions of turbulence models for separated flows, explores the physical properties that impact predictions, and investigates their specific mechanisms.
Article
Mechanics
Mohammad Sarabian, Mohammadhossein Firouznia, Bloen Metzger, Sarah Hormozi
JOURNAL OF FLUID MECHANICS
(2019)
Article
Engineering, Mechanical
Ahmadreza Rashedi, Guillaume Ovarlez, Sarah Hormozi
EXPERIMENTS IN FLUIDS
(2020)
Article
Mechanics
Y. Madraki, A. Oakley, A. Nguyen Le, A. Colin, G. Ovarlez, S. Hormozi
JOURNAL OF RHEOLOGY
(2020)
Article
Multidisciplinary Sciences
Guillaume Ovarlez, Anh Vu Nguyen Le, Wilbert J. Smit, Abdoulaye Fall, Romain Mari, Guillaume Chatte, Annie Colin
Article
Chemistry, Multidisciplinary
Julien Laurens, Julien Jolly, Guillaume Ovarlez, Helene Fay, Thomas Chaussee, Paul Sotta
Article
Mechanics
Mohammadhossein Firouznia, Michael J. Miksis, Petia M. Vlahovska, David Saintillan
Summary: This study analyzes the stability of the interface between two immiscible fluids subject to a tangential electric field and a stagnation point flow, demonstrating the subtle interplay between charge convection and conduction. The research shows how the coupling of flow and interfacial charge dynamics can lead to nonlinear phenomena such as tip formation and the growth of charge density shocks.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Leila Khacef, Philippe Legros, Pascal Herve, Guillaume Ovarlez, Yaocihuatl Medina-Gonzalez
Summary: In this study, organogels prepared using the N-oleyldiamide molecule were examined in various types of solvents to understand the effects of solvent polarity on the internal structure and rheological properties. It was found that the solvent proticity is a key parameter influencing the organogel properties, with the elastic modulus increasing significantly with higher polar solvents. Cryo-SEM and WAXS techniques were utilized to investigate the structures and supramolecular self-assembly of the organogels.
Article
Physics, Fluids & Plasmas
Mohammadhossein Firouznia, David Saintillan
Summary: This study investigates the stability and dynamics of a system of three superimposed layers of two immiscible fluids subject to an electric field, using a model that captures the interfacial charge dynamics. By performing linear stability analysis and numerical simulations, the research demonstrates how coupling of flow and surface charge transport in different modes of instability can give rise to nonlinear phenomena such as tip streaming or pinching of the film into droplets.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Chemistry, Physical
Clement Robin, Cedric Lorthioir, Azad Erman, Javier Perez, Abdoulaye Fall, Guillaume Ovarlez, Catherine Amiel, Clemence Le Coeur
Summary: This work focuses on understanding the interactions between three differently functionalized silica nanoparticles and PMAA in aqueous media. The results showed that the amine-functionalized silica nanoparticles had stronger adsorption with PMAA due to a combination of electrostatic and hydrophobic interactions.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Mechanics
C. Garat, S. Kiesgen de Richter, P. Lidon, A. Colin, G. Ovarlez
Summary: This paper investigates the impact of vibrations on the behavior of dense granular suspensions. It is found that vibrations can tune the transition from solidlike to liquidlike behavior in these suspensions. Experimental results show that under vibrations, the suspensions of frictional particles exhibit liquidlike behavior similar to that of nonvibrated suspensions of frictionless particles. As the shear rate increases, the suspensions undergo shear thickening and eventually experience shear-jamming, where vibrations no longer have an impact.
JOURNAL OF RHEOLOGY
(2022)
Article
Chemistry, Physical
Anh Vu Nguyen Le, Adrien Izzet, Guillaume Ovarlez, Annie Colin
Summary: This study investigates the non-Newtonian behaviors of hard sphere suspensions in Newtonian fluids, and reveals different macroscopic and microscopic behaviors of the suspensions when immersed in different solvents. The study demonstrates the impact of interparticle contact forces on the macroscopic behavior and proposes several particle-scale mechanisms. It provides new quantitative data for micromechanical models and simulations, challenges the interpretation of previous experiments, and emphasizes the systematic characterization of interparticle normal and tangential forces in studying hard sphere suspensions in Newtonian fluids.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Polymer Science
Clement Robin, Cedric Lorthioir, Abdoulaye Fall, Guillaume Ovarlez, Catherine Amiel, Clemence Le Coeur
Summary: This study investigates the temperature-composition phase diagram of PMAA and the formation of phase-separated nanostructures, revealing the mechanism and characteristics of phase separation in the semi-dilute regime.
Article
Chemistry, Physical
Stephanie Deboeuf, Lucie Ducloue, Nicolas Lenoir, Guillaume Ovarlez
Summary: Dispersing solid hard particles in an elasto-plastic material leads to strain hardening and Bauschinger effect. Strain hardening refers to the progressive strengthening of a material during plastic deformation, usually associated with ductility. The Bauschinger effect means that the material resistance is larger in the direction of imposed flow, and it is related to particle-pair distribution functions.
Article
Engineering, Petroleum
Steven Meeker, Arthur Gadon, Nidal Ben Abdelouahab, Guillaume Ovarlez, Hugues Bodiguel
Article
Engineering, Chemical
Ahmadreza Rashedi, Mohammad Sarabian, Mohammadhossein Firouznia, Dallas Roberts, Guillaume Ovarlez, Sarah Hormozi
Article
Mechanics
Mateus C. Guimaraes, Fernando T. Pinho, Carlos B. da Silva
Summary: A new theory is proposed to describe the conformation state of polymer chains in free turbulent shear flows of viscoelastic fluids. The theory shows the existence of minimum and maximum solvent dissipation reduction asymptotes and four different polymer deformation regimes, based on self-similarity arguments and new scaling relations for the turbulent flux of conformation tensor. In addition, analytical solutions for the self-similar transverse profiles of the conformation tensor components are obtained. The theory is validated through excellent agreement with direct numerical simulations employing the FENE-P rheological model.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2024)
