Article
Physics, Fluids & Plasmas
Nelson Poumaere, Benoit Pier, Florence Raynal
Summary: We investigate the distributions of residence time for in-line chaotic mixers and find that they all possess a t(-3) tail, significantly different from Gaussian distribution. We propose a new measure, mean absolute deviation, for the width of the distribution, and show its convergence in the limit of large sample size. Additionally, we analyze the performance of different in-line mixers in terms of residence time when varying the number of elements and the shape of the cross section.
Article
Mechanics
Mahan Raj Banerjee, Ganesh Subramanian
Summary: In the Stokesian limit, the streamline topology around a single neutrally buoyant sphere is identical to that of pair-sphere pathlines, while the topology of pathlines around a neutrally buoyant freely rotating spheroid is significantly different. The motion of a spheroid in a simple shear flow is determined by its orbit constant, leading to different categories of fluid pathlines with varying behaviors.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
Zhongqiao Gan, Haitao Liu, Yaqing Wang, Tingting Tao, Mengqian Zhao, Jianhua Qin
Summary: This study presents a simple strategy for the in situ generation of porous GelMA microgels as cell carriers by integrating the placeholder of PEO and chaotic advection effect in microfluidic devices. The size and porosity of the microgels can be precisely controlled by changing the flow rates of the continuous and dispersed phases. The microgels show high biocompatibility and potential as microcarriers for various cell types, as demonstrated by the viability, spreading, and proliferation of human mesenchymal stem cells and umbilical vein endothelial cells cultured on their surface.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Biochemical Research Methods
Valentina Biagioni, Claudia Venditti, Alessandra Adrover, Massimiliano Giona, Stefano Cerbelli
Summary: The study explores methods to reduce Taylor-Aris dispersion. It is found that Taylor-Aris phenomenon can be completely suppressed in the limit of globally chaotic kinematics.
JOURNAL OF CHROMATOGRAPHY A
(2022)
Article
Physics, Fluids & Plasmas
Jingang Qu, Daniel Henry, Sophie Miralles, Valery Botton, Florence Raynal
Summary: In this numerical study, the mixing properties of an acoustic driven flow in a parallelepipedic cavity with square basis are investigated. Depending on the power of the acoustic source, the flow field may be steady, periodic or chaotic. The results show that steady and periodic flow fields allow for chaotic advection, and acoustic streaming can be used as a nonintrusive tool for efficient mixing.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Engineering, Chemical
Wensheng Wang, Mingxin Li, Cong Xu
Summary: This study demonstrates the significant role of vertical chaotic advection in the mixing process of 3D OFMs, which promotes overall mixing. The findings have important implications for improving the mixing efficiency of micromixers.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Yu He, Xiaobin Zhan, Baojun Shen, Zhibin Sun, Jiecai Long, Yili Yang, Xiwen Li
Summary: A twin cam mixer system equipped with two triangular cams was studied to investigate the effect of operating conditions on chaotic advection. Particle Image Velocimetry was used to study flow characteristics under different operating modes. The results showed that counter-rotating mode outperformed co-rotating mode, and more global chaotic advection could be achieved with higher average angular velocity, higher disturbance quantity, and lower disturbance frequency.
Article
Engineering, Chemical
Jo Eun Park, Seon Yeop Jung, Tae Gon Kang
Summary: This paper numerically explores the potential of patterned membranes inducing chaotic advection to enhance the efficiency of reverse osmosis (RO) filtration. Four different membrane patterns were compared in terms of filtration performance and the herringbone pattern (HP) and staggered herringbone pattern (SHP) were found to significantly enhance filtration performance compared to the flat surface (FS) and lateral pattern (LP). Chaotic advection induced by the HP and SHP effectively suppressed concentration polarization and enhanced the energy efficiency of RO filtration.
Article
Thermodynamics
Abbas Aldor, Yann Moguen, Kamal El Omari, Charbel Habchi, Pierre-Henri Cocquet, Yves Le Guer
Summary: In this paper, an innovative sine-helical heat exchanger is presented, and numerical analysis demonstrates its improved temperature homogeneity and convective heat transfer efficiency compared to a classical helical heat exchanger.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mathematics, Applied
A. A. Didov, M. Yu. Uleysky, M. V. Budyansky
Summary: This study focuses on a nonlinear dynamical system with 3/2 degrees of freedom, which consists of a point vortex and an unsteady background flow. The background flow is composed of two sinusoidal components with different frequencies and amplitudes. The system, with a separatrix loop in the phase portrait, serves as the simplest model for chaotic scattering of passive tracers on a topographic vortex in the ocean. The study reveals that the passive tracers enter and leave the vortex region in portions depending on the variation of the amplitudes of the two sinusoidal components. The frequency of escape and the size of these portions are determined by the parameters of the background flow. Furthermore, the study shows that the structure of the fractal-like scattering function changes through the formation or disappearance of segments, depending on the relationship between the frequencies of the perturbation.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Thermodynamics
Lakhdar Aidaoui, Yahia Lasbet, Fatih Selimefendigil
Summary: This study characterizes the efficiency and entropy generation of nanofluid forced convection flow with chaotic perturbations under the influence of a non-uniform magnetic field. The combined effects of chaotic advection, nanoparticles, and non-uniform magnetic field were found to enhance fluid flow performance. The co-effect of magnetic intensity, orientation, and application mode was shown to stimulate energy system performance, with entropy generation mainly attributed to thermal irreversibilities in laminar flow.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Chemistry, Analytical
Chen-Hsun Weng, Pei-Pei Hsu, An-Yu Huang, Jr-Lung Lin
Summary: This study aimed to design and fabricate planar constricted-expanded structures integrated into paper-based channels to improve mixing performance. Experimental and numerical results showed that the proposed structures can successfully mix fluids, indicating the potential importance of passive paper-based mixers in microfluidic devices.
Article
Engineering, Chemical
M. M. Overd, S. C. Generalis
Summary: This paper discusses the application of chaos in viscous fluid mixing and investigates the effect of particle divergence and separation on the degree of disorder in the flow domain. By developing characteristic plots and concepts, engineers can predict and characterize the degree of disorder in future industrial chaotic mixing equipment.
INTERNATIONAL POLYMER PROCESSING
(2022)
Article
Energy & Fuels
Ekta Tripathi, Promod Kumar Patowari, Sukumar Pati
Summary: This study proposes three innovative spiral micromixers and investigates their mixing and pressure drop characteristics under different Reynolds numbers. SE and RS micromixers show better mixing performance and higher mixing index compared to the SS micromixer. The width of the mixers has a greater impact on the mixing index than the depth.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2021)
Article
Mathematics, Applied
L. C. Souza, A. C. Mathias, I. L. Caldas, Y. Elskens, R. L. Viana
Summary: The E x B drift motion in tokamaks provides valuable information on turbulence-driven anomalous transport. Chaotic orbits occur in the drift motion dynamics, resulting in large-scale drifts. By studying the structures of fractal escape basins, we use numerical diagnostics to quantify the final-state uncertainty. We estimate the escape basin boundary dimension, quantify final-state uncertainty, and verify the Wada property for multiple escape basins using a grid approach.
Article
Mechanics
Xander M. de Wit, Andres J. Aguirre Guzman, Herman J. H. Clercx, Rudie P. J. Kunnen
Summary: Using direct numerical simulations, this study investigates the transitions between turbulent states in rotating Rayleigh-Benard convection. The focus is on the change from a three-dimensional flow state to a quasi-two-dimensional condensate called the large-scale vortex (LSV). The study examines the strength of the LSV in terms of order parameters and evaluates the energetic content in the flow and the upscale energy flux. The results reveal discontinuous transitions, the presence of a hysteresis loop, and a memoryless abrupt growth dynamics. Additionally, a discontinuous transition of the energy transport into the largest mode of the system coincides with the creation of the condensate state.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Chemical
Guy Metcalfe, Daniel Lester, Michael Trefry
Summary: This article introduces a method based on dynamical systems theory to analyze and understand complex flow phenomena in porous media flow and transport. By studying the motion of fluid particle trajectories, the characteristics of flow and mixing can be revealed, which have significant impacts on solute transport. The latest experimental methods allow for visualizing these flow phenomena, providing new tools and techniques for the study of porous media flow.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Thermodynamics
R. Lensvelt, M. F. M. Speetjens, H. Nijmeijer
Summary: This study focuses on the development of a dedicated flow-control strategy for fast heating of a cold fluid via a hot boundary. The study reveals the importance of fluid deformation in heat transfer and proposes a control problem solution. The results show that the adaptive flow reorientation significantly accelerates fluid heating, surpassing conventional periodic schemes in terms of effectiveness.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Antonio G. Checa, Carlos Pimentel, Katarzyna Berent, Paula Ramos-Silva, Alejandro B. Rodriguez-Navarro, Julyan H. E. Cartwright, Claro Sainz-Diaz
Summary: This study reexamines the morphological characteristics of the fibers in planktonic gastropods and provides direct evidence of their helical coiling through fracture and polished sections. The researchers also develop a 3D model that is consistent with the observed patterns.
Article
Mathematics, Applied
Patrick Wright, Jitse Niesen, Rob Sturman
Summary: Rigorous, elementary upper and lower bounds on the Lyapunov exponents of a parametrised family of linked twist maps are explicitly obtained for a specific range of parameter values. The method used relies on the existence of invariant cones for specific products of the shear maps and the partitioning of the overlap region of the two annuli based on return time. The accuracy of this method is improved by considering preceding sequences of matrices on the orbits.
Editorial Material
Engineering, Chemical
Marco Dentz, Daniel R. Lester, Michel F. M. Speetjens
TRANSPORT IN POROUS MEDIA
(2023)
Article
Energy & Fuels
Mengting Jiang, Michel Speetjens, Camilo Rindt, David Smeulders
Summary: This study develops a data-based compact model for predicting fluid temperature in district heating pipeline networks. The model, called reduced-order model (ROM), is obtained by reducing the energy conservation law for each pipe segment to an input-output relation between pipe temperatures, which can be determined from training data. The ROM is applicable to various pipe configurations involving 3D unsteady heat transfer and 3D steady flow as long as heat-transfer mechanisms are linearly dependent on temperature. The study demonstrates the successful identification and accurate prediction capability of the ROM using computational training data for both single-pipe configurations and realistic systems.
Article
Mechanics
Jean-Luc Thiffeault
Summary: In passive scalar transport, it is important to parameterize the effect of a fluctuating component of the flow to overcome limited resolution. One commonly used parameterization is the local effective diffusivity, which relates the advective flux to gradients of the mean concentration. Souza et al. introduce a stochastic framework where the local effective diffusivity is replaced by an exact effective diffusivity operator, allowing for quantification of deviations from the local approximation and suggesting areas for improvement and novel closure models.
JOURNAL OF FLUID MECHANICS
(2023)
Review
Materials Science, Multidisciplinary
Julyan H. E. Cartwright, Antonio G. Checa, Michael J. Vendrasco
Summary: Over 500 million years ago, molluscs developed shells as biomineral exoskeletons in response to the evolution of predators developing jaws and other novel means of devouring them. These shells are composed of multiple layers with specific microstructures, resulting from the coevolution with increasingly deadly predators. The study of molluscan biomineralization provides insights into how a biological process generates complex structures.
Article
Multidisciplinary Sciences
Silvia Holler, Stuart Bartlett, Richard J. G. Loeffler, Federica Casiraghi, Claro Ignacio Sainz Diaz, Julyan H. E. Cartwright, Martin M. Hanczyc
Summary: This paper investigates the features of alkaline hydrothermal vents and their significance in the origins of life. By integrating fatty alcohol decanol into inorganic minerals, novel three-dimensional structures were produced, and it has been demonstrated that the interaction between fatty alcohols and inorganic mineral structures may have played a crucial role in the formation of protocells.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Review
Biochemistry & Molecular Biology
Julyan H. E. Cartwright
Summary: This article explores whether nature uses quantum mechanics in cilia to enhance the sensitivity of the mechanism of left-right symmetry breaking during development in vertebrates. The author evaluates whether mechanosensing, or the detection of a left-right asymmetric signal through mechanical stimulation of sensory cilia rather than biochemical signaling, may be functioning through quantum mechanics in the embryonic left-right organizer of the vertebrate bodyplan. They conclude that quantum biology may have a potential role in mechanosensing in cilia. The system may be limited by quantum noise rather than classical thermal noise, and an amplification process could provide active cooling.
PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Nimish Pujara, Jean-Luc Thiffeault
Summary: This study models the motion of particles such as microplastics and phytoplankton in a wavy environment and examines how the particle shape and buoyancy affect the particle orientation, drift, and dispersion driven by waves. The findings show that particles have a wave-induced preferential orientation, reduced settling velocity, and increased horizontal dispersion under wave action.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Chemistry, Multidisciplinary
Carlos Pimentel, Mingchuan Zheng, Julyan H. E. Cartwright, C. Ignacio Sainz-Diaz
Summary: Considering the increasing importance of chemobrionics and the growing number of published papers since 2015, it has become necessary to create a database cataloguing all the papers published to date. This chemobrionics database lists the synthesis of chemical gardens based on their anion, cation, and experimental protocol. Its aim is to promote the study and dissemination of chemical gardens and explore new experimental avenues in chemobrionics. Due to the continuous growth of this field, the database is constantly updated.
Article
Chemistry, Physical
Sergio Teston-Martinez, Teresa Huertas-Roldan, Pamela Knoll, Laura M. Barge, C. Ignacio Sainz-Diaz, Julyan H. E. Cartwright
Summary: This study reports on the formation of self-assembled microfluidic labyrinths in a vertical 2D Hele-Shaw reactor using two chemical garden reaction systems. The formation of labyrinths and the growth modes of the precipitate were dependent on the concentration of sodium silicate. The results suggest potential applications in microfluidics and materials science.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Mechanics
Giuseppe Di Labbio, Jean-Luc Thiffeault, Lyes Kadem
Summary: The flow patterns in the heart, especially in relation to health and disease, have attracted a lot of attention. Modern fluid dynamics analyses explain how inefficient flow patterns can lead to adverse effects. However, translating these analyses into the clinical setting remains difficult. In this experiment, the concept of using braids of random and sparse particle trajectories is proposed and demonstrated as an intuitive and practical description of cardiovascular flows. The study also reveals the highly effective blood mixing properties of a healthy flow pattern in a left ventricle model, which can be compared to diseased flow models to evaluate energetic efficiency.
