Article
Mechanics
Bohan Wang, Weiquan Jiang, Guoqian Chen
Summary: This study directly investigates the gyrotactic trapping mechanism in representative simple shear flows by studying the fundamental Smoluchowski equation, thus bridging the gap between the continuum approach and individual-based models. The influences of varying shear rate and boundary effect are analyzed, and the time-dependent nature of the average swimming orientation with fixed local shear is highlighted. The variations of the characteristic time of the transient thin layer and the consideration of micro-swimmer sedimentation are also discussed.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Multidisciplinary Sciences
Chih-Tang Liao, An -Jun Liu, Yeng-Long Chen
Summary: This study investigates the flow-induced structural organization in dilute suspensions of red blood cells under confined shear flow. The results show that hydrodynamic interaction between the discoid particles leads to the formation of layered RBC chains and synchronized rotating RBC pairs. The presence of more pairs is observed with increasing volume fraction, and stronger shear stress disrupts the structural arrangements.
Article
Thermodynamics
Q. Shu, R. Kneer, W. Rohlfs
Summary: Different physical models have been established to describe thermal conductivity enhancements in suspensions with micro- and nanoparticles over the past three decades. However, the influence of shear has not been considered in these models, despite experimental observations of its impact at very high shear rates. The finite element method is utilized in this study to evaluate how shear-induced particle rotation and the velocity field around the rotating particle contribute to thermal conductivity enhancement.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Chemical
Kohei Ohie, Taiki Yoshida, Yuji Tasaka, Yuichi Murai
Summary: Flow prediction of complex fluids in a circular pipe was successfully conducted using a velocity-profiling-assisted rheometer. The obtained results demonstrated the high industrial practicality of this method for complex fluids that are outside the application scope of a standard rheometer.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Mechanics
Hanliang Guo, Hai Zhu, Ruowen Liu, Marc Bonnet, Shravan Veerapaneni
Summary: This article introduces a computational approach to determine the optimal slip velocities on any given shape of an axisymmetric micro-swimmer in a viscous fluid. By simplifying the PDE-constrained optimization problem into a quadratic optimization problem, the solution is found using a high-order accurate boundary integral method. Prolate spheroids were identified as the most efficient micro-swimmer shapes for a given reduced volume, and a shape-based scalar metric was proposed to determine the optimal slip behavior on a given shape.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
A. Dhar, P. S. Burada, G. P. Raja Sekhar
Summary: This study analyzes the swimming characteristics of an active swimmer in a dilute and disperse suspension modeled as an effective Brinkman medium. Emphasis is placed on the impact of the interior domain of an individual swimmer and its neighbors, along with predicting effective resistivity and analyzing propulsion speed and efficiency. Results show a noticeable increase in migration velocity and swimming efficiency at optimum occupancy, and rheological characteristics such as effective viscosity are highlighted.
Article
Chemistry, Physical
Andrea Scotti
Summary: The volume fraction occupied by colloids in suspension determines their phase behavior, with soft compressible colloids presenting challenges in accurately defining their real volume due to their surface fuzziness and ability to interpenetrate with neighboring particles.
Article
Physics, Multidisciplinary
Eric Lauga, Thanh Nghi Dang, Takuji Ishikawa
Summary: The research shows that biased swimming microorganisms can exhibit instability in their position, leading to periodic transverse oscillations. Theoretical predictions suggest that the most unstable wavelength is twice the distance between microorganisms, and the growth rate of the instability is proportional to the stresslet magnitude.
Article
Chemistry, Physical
Xinhao Li, Zihua Hu, Yang Wang, Changjiang Qin, Zhiyuan Xu, Xiaogao Chen, Shicheng Wu, Yu Tu, Yi Wang
Summary: This paper systematically investigates the shear-thickening and shear-thinning rheological properties of a non-Newtonian fluid composed of polyethylene glycol (PEG) mixed with nano-silica (Nano-SiO2) using dissipative particle dynamics (DPD) method. At low shear rates, the molecular chains of PEG are stretched, resulting in shear-thinning behavior. At high shear rates, increased contact and collision probability between Nano-SiO2 beads leads to particle aggregation and shear-thickening behavior. This study provides insights into the microscopic mechanisms of non-Newtonian fluid rheological behavior and contributes to intelligent applications.
Article
Chemistry, Physical
Jaideep Katuri, Alexey Snezhko, Andrey Sokolov
Summary: Acoustically powered bubble microswimmers suspended in liquid crystals can self-propel and induce topological defects, with their velocity and swimming direction controlled by the acoustic field.
Article
Mechanics
Jingran Qiu, Navid Mousavi, Kristian Gustavsson, Chunxiao Xu, Bernhard Mehlig, Lihao Zhao
Summary: Marine micro-organisms face challenges in navigation and survival in complex flow patterns, with studies using reinforcement learning to determine optimal strategies. Interestingly, motile micro-organisms primarily rely on local cues for survival decisions rather than accessing global information.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Bohan Wang, Weiquan Jiang, Guoqian Chen
Summary: In this study, we investigate the bidirectional coupling effect between gravity-driven flow and microorganism concentration by solving the Smoluchowski equation and the Navier-Stokes equation simultaneously. The results show that this coupling effect significantly enhances the velocity and concentration of microorganisms in the central region, as well as the drift velocity and dispersivity. However, in upwelling flows, the dominant influence of the no-slip boundary condition imposed at the wall limits the coupling effect between gravity-driven flow and microorganism concentration.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Chemistry, Physical
Arghyadeep Paul, N. R. Aluru
Summary: The study investigates the impact of nonlocal shear stress on gravity-driven isothermal flow in nanochannels under strong confinement. The local average density model is used and the fluid's viscosity kernel is estimated using the sinusoidal transverse force method. A continuum model is proposed to solve the nonlocal hydrodynamics problem and its solutions are qualitatively compared with the results of non-equilibrium molecular dynamics simulations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Md Samsuzzaman, Ahmed Sayeed, Arnab Saha
Summary: We study the suspension of rough, circular particles in two dimensions under athermal conditions. By simulating the system with different magnitudes of external drive, we find that oppositely moving macroscopic lanes only occur within a moderate range of external drive. The no-lane state reenters at high external drives due to the roughness of individual particles and the friction between them.
Article
Thermodynamics
Qian Fu, Hao Chen, Chao Xiao, Yun Huang, Ao Xia, Xun Zhu, Qiang Liao
Summary: The study focused on the effective thermal conductivity of microalgae suspension in shear flow, revealing an increase in thermal conductivity with higher shear rates. An empirical formula correlation was proposed to predict the effective thermal conductivity in shear flow, taking into account various factors such as volume fraction, thermal conductivity, shear rate, and particle Peclet number.
APPLIED THERMAL ENGINEERING
(2021)
Article
Water Resources
Konstantin Lipnikov, David Moulton, Daniil Svyatskiy
ADVANCES IN WATER RESOURCES
(2016)
Article
Mathematics, Applied
Vitaliy Gyrya, Konstantin Lipnikov, Gianmarco Manzini
ESAIM-MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS-MODELISATION MATHEMATIQUE ET ANALYSE NUMERIQUE
(2016)
Article
Mathematics, Applied
Blanca Ayuso de Dios, Konstantin Lipnikov, Gianmarco Manzini
ESAIM-MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS
(2016)
Article
Computer Science, Interdisciplinary Applications
Konstantin Lipnikov, Gianmarco Manzini, J. David Moulton, Mikhail Shashkov
JOURNAL OF COMPUTATIONAL PHYSICS
(2016)
Article
Mathematics, Applied
Andrea Cangiani, Vitaliy Gyrya, Gianmarco Manzini
SIAM JOURNAL ON NUMERICAL ANALYSIS
(2016)
Article
Computer Science, Interdisciplinary Applications
Eugenia Kim, Konstantin Lipnikov
JOURNAL OF COMPUTATIONAL PHYSICS
(2017)
Article
Computer Science, Interdisciplinary Applications
K. Lipnikov, G. Manzini
JOURNAL OF COMPUTATIONAL PHYSICS
(2014)
Article
Computer Science, Interdisciplinary Applications
Konstantin Lipnikov, Gianmarco Manzini, Mikhail Shashkov
JOURNAL OF COMPUTATIONAL PHYSICS
(2014)
Article
Computer Science, Interdisciplinary Applications
Nathaniel R. Morgan, Konstantin N. Lipnikov, Donald E. Burton, Mark A. Kenamond
JOURNAL OF COMPUTATIONAL PHYSICS
(2014)
Article
Mathematics, Applied
Vitaliy Gyrya, Konstantin Lipnikov, Gianmarco Manzini, Daniil Svyatskiy
MATHEMATICAL MODELS & METHODS IN APPLIED SCIENCES
(2014)
Article
Mathematics, Applied
Konstantin Lipnikov, Danail Vassilev, Ivan Yotov
NUMERISCHE MATHEMATIK
(2014)
Proceedings Paper
Mathematics, Applied
Konstantin Lipnikov, Gianmarco Manzini
BUILDING BRIDGES: CONNECTIONS AND CHALLENGES IN MODERN APPROACHES TO NUMERICAL PARTIAL DIFFERENTIAL EQUATIONS
(2016)
Proceedings Paper
Engineering, Multidisciplinary
Rao V. Garimella, William A. Perkins, Mike W. Buksas, Markus Berndt, Konstantin Lipnikov, Ethan Coon, John D. Moulton, Scott L. Painter
23RD INTERNATIONAL MESHING ROUNDTABLE (IMR23)
(2014)