Article
Engineering, Marine
Hongwei An, Xiaoyuan Hu, Scott Draper, Liang Cheng, Binsar Lubis, Mehrdad Kimiaei
Summary: A new method is proposed to determine the hydrodynamic force coefficients of an object by testing an articulated concrete mattress on a flat surface. The method uses a pulley system and a load cell to measure the force required to pull the mattress, and can accurately calculate the force coefficients while eliminating the difficulties associated with traditional test methods.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Analytical
Yunjae Park, Changhyun Jung, Myeongseok Seong, Minjae Lee, Dongil Dan Cho, Taehyun Kim
Summary: A new method utilizing a pre-calibrated voltage divider to measure the absolute amplitude of large RF voltages in ion traps is proposed, eliminating uncertainty caused by numerical simulations. Experimental validation showed the effectiveness of the method, making it applicable to most ion trap experiments.
Article
Physics, Condensed Matter
Radost Waszkiewicz, Maciej Lisicki
Summary: In this study, we conduct a detailed theoretical analysis of the behavior of rod-like molecules attracted by charged nanopores, estimating time scales for Brownian and electrostatic translations. We find that Brownian motion becomes negligible at certain distances, numerically determining trajectories of the nano-rod in the pore region to explore the effects of anisotropic mobility. This helps determine the range of directions from the pore where hydrodynamic interactions with the boundary shape approach dynamics, requiring consideration in detailed modeling.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Mechanics
Pan Jia, Bruno Andreotti, Philippe Claudin
Summary: This study theoretically investigates the hydrodynamic roughness induced by a two-dimensional modulated surface and predicts the effective hydrodynamic roughness for different wavelengths. It also explores the smooth-rough transition of a flat surface by considering the surface corrugation. Additionally, the results are applied to natural patterns, providing insights into dissolution bedforms and roughness hierarchy in superimposed ripples and dunes.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Mechanical
F. Quintero, A. F. Doval, A. Goitia, R. Vazquez, K. Crespo, R. Barciela, M. Fernandez-Arias, F. Lusquinos, A. Otto, J. Pou
Summary: High-performance fibers are essential for improving the mechanical properties of composite materials. The development of high-strength nanofibers has the potential to create nanocomposites with outstanding features. However, the production of continuous glass nanofibers that can be efficiently processed for manufacturing nanocomposites is still a challenge. The Cofiblas technique has been demonstrated as a method for producing continuous glass nanofibers with unlimited length, but the design of the gas nozzle is crucial for the feasibility of the process.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Mechanics
Santanu Kumar Sahoo, Hrishikesh Gadgil
Summary: Gas-liquid coaxial injectors involve a shear layer between a gas stream and a liquid stream, resulting in self-pulsation of the spray. By applying acoustic forcing to the gas jet and analyzing the response, we can gain insights into the dynamics of atomization and potentially control it.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Guang-hang Wang, Yan Du, Zhi-jian Xiao, Jian Huang, Zhi-ying Wang, Hong-chen Li, Jing-zhu Wang, Yi-wei Wang
Summary: When an oscillating bubble bursts near a water surface, it releases high-pressure gas and forms a splash sheet and an open cavity. The dynamics of the splash sheet resulting from the bursting of the oscillating bubble are still not well understood. In this study, we conduct numerical simulations using OpenFOAM software to accurately capture the gas-liquid interface and flow structure. Experimental validation is also performed. Two patterns of splash closures, open and sealed, are identified based on whether the splash sheet completely closes. The Rayleigh-Taylor instability is found to induce the bubble bursting.
JOURNAL OF HYDRODYNAMICS
(2022)
Article
Physics, Multidisciplinary
Basant K. Jha, Dauda Gambo
Summary: The research examines the mass transport phenomenon of Saffman's dusty fluid model for transient magnetohydrodynamics fluid flow of a binary mixture passing through an annular duct, with a focus on the theoretical exploration of the role of velocity of applied magnetic field. Contrary to the expected classical effect of boosting the Hartmann number on velocity, it is found that an overwhelming presence of velocity of applied magnetic field increases both components of flow (fluid and dust phase) and skin friction.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Mechanics
Dipankar Paul, Mouzakkir Hossain, Harekrushna Behera
Summary: This paper investigates the linear and weakly nonlinear stability of an odd-viscosity-induced shear-imposed falling film over an inclined plane. The linear stability is examined numerically using the Chebyshev spectral collocation approach, revealing that instability increases with increasing external shear in the streamwise direction. However, when external shear rises in the reverse flow direction, wave energy is dissipated and the surface wave stabilizes. The study also applies the longwave expansion method to calculate the nonlinear surface deformation and finds that odd viscosity can stabilize the fluid flow instability caused by a positive shear force.
Article
Chemistry, Physical
Jiao Ye, Si-Cong Tan, Lei Wang, Jing Liu
Summary: The Marangoni effect is commonly used to manipulate droplets, while the movement of liquid metal is primarily driven by the viscous forces of the solution. This study reveals the mechanism of liquid metal movement under an electric field, laying the groundwork for applications in pumping, fluid mixing, and other microfluidic fields.
Article
Engineering, Aerospace
Xin Zhang, Yong Huang
Summary: Surface dielectric barrier discharge plasma actuators are favored for aircraft flow control due to their advantages in continuous and burst modes. Understanding the flowfield generated by these plasma actuators is crucial for improving their control effects. In this study, the flowfield created by a single asymmetrical plasma actuator in still air is investigated using a two-dimensional time-resolved particle image velocimetry device. It is found that a pulsed velocity is created by the plasma actuator in continuous mode near the dielectric surface, which results in large-size disturbances and benefits flow control. The formation of this pulsed velocity is speculated to be related to the coupling effect between the entrainment of the starting vortex and the induced body force.
Article
Computer Science, Information Systems
Yifu Guo, Junyang Deng, Jiebin Niu, Chunhui Duan, Shibing Long, Mengmeng Li, Ling Li
Summary: Field-effect transistors based on organic semiconducting materials (OFETs) have advantages such as mechanical flexibility, low manufacturing cost, and improved device parameters. However, a significant problem in OFETs is the shift in threshold voltage (V-TH). This study demonstrates that the V-TH of polymer OFETs with SiO2 dielectric is noticeably shifted by applying a large gate voltage, indicating the presence of charge trappings in the SiO2 bulk. The generality of this observation is further confirmed with other conjugated polymers.
Article
Water Resources
Pratyaksh Karan, Uddipta Ghosh, Yves Meheust, Tanguy Le Borgne
Summary: Mixing-induced reaction fronts are crucial in subsurface processes and mechanical dispersion leads to faster front propagation and enhanced reaction rate. These findings have broad implications for field conditions at various temporal and spatial scales.
ADVANCES IN WATER RESOURCES
(2023)
Article
Engineering, Geological
Xu Deng, Sizhong He, Zhouhong Cao, Tao Wu
Summary: The study used a numerical tank to simulate the hydrodynamic response of a sea-wall subjected to artificial submarine landslide-induced tsunamis. The results showed that the artificial landslide generated two successive wave crests, with the sea-wall experiencing stronger hydrodynamic response under the second crest.
Article
Mechanics
Rodrigo B. Reboucas, Alexander Z. Zinchenko, Michael Loewenberg
Summary: An exact pairwise hydrodynamic theory is developed for studying the flow-induced spatial distribution of particles in dilute polydisperse suspensions. The theory predicts a boundary layer where the shear rate vanishes, with linearly vanishing drift velocities and non-vanishing diffusivities. Particle trajectories and distributions are analytically integrated for particles with symmetry-breaking contact interactions. The predictions agree well with experiments in suspensions up to approximately 20% volume fraction.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mathematics, Applied
Nan Nan, Guohui Hu
APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION
(2019)
Article
Chemistry, Multidisciplinary
J. D. Sherwood, S. Ghosal
Article
Chemistry, Multidisciplinary
S. Ghosal
Article
Nanoscience & Nanotechnology
Jun Xie, Guo-Hui Hu
Summary: The study focuses on the use of microfluidics for cell squeezing and utilizes numerical simulations to determine the gating region and appropriate tension on the membrane. Results highlight the importance of pressure setting in system design and optimization, while the occurrence of secondary peak under flow conditions is attributed to the elastic recovery of the membrane.
MICROFLUIDICS AND NANOFLUIDICS
(2021)
Article
Chemistry, Multidisciplinary
Doyel Pandey, Somnath Bhattacharyya, Sandip Ghosal
Summary: The study investigates the charge selective properties of a long planar nanochannel with an embedded charged section, defining the properties using a dimensionless quantity called fractional blockage. The research explores how the fractional blockage is influenced by dimensionless parameters related to the charge state and channel geometry. In the limit of strongly overlapped wall Debye layers, analytical expressions for the fractional blockage show good agreement with numerically computed values, offering insights for the design of nanofluidic devices with diverse applications.
Article
Mechanics
J. D. Sherwood, S. Ghosal
Summary: The electrophoresis of a tightly fitting sphere of radius a along the centreline of a liquid-filled circular cylinder of radius R is studied, with a gap width h(0) = R - a << a. The pressure difference between the front and rear of the sphere causes an additional volumetric flow of liquid along the cylinder, increasing the electrophoretic velocity of the sphere. In the presence of N identical, well-spaced spheres, the electrophoretic velocity of the spheres increases with N.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Dong-qing Si, Xin-yue Liu, Jin-bo Wu, Guo-hui Hu
Summary: The study investigates the conformation transition of double-strand DNA (dsDNA) in electrolytic nanodroplets using molecular dynamics simulation. The transition is found to be related to the buckling of polymer molecules, confinement of the nanodroplet, and ionic concentration in the electrolyte.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Analytical
Xindi Sun, Wei Li, Xiuqing Gong, Guohui Hu, Junyi Ge, Jinbo Wu, Xinghua Gao
Summary: This study investigated the impact of different microstructure topographical cues on inducing neuronal differentiation in vitro using PC12 cells. Results showed significant differences in differentiation under different topographic cues, with potential for guiding axon extension. Furthermore, the feasibility of combining topographic cues with microfluidic chips for neural differentiation research was discussed.
Article
Polymer Science
Yu Lu, Xin-Yue Liu, Guo-Hui Hu
Summary: This study numerically investigates the diffusion of nanoparticles in an unentangled polymer network using single-particle dissipative particle dynamics (DPD). The results show that the deformation due to junction deviation significantly affects the diffusion of nanoparticles. Based on the theory of continuum mechanics, a nonlinear spring is proposed to describe the relationship between the deformed energy and the junction deviation. A double-spring model is suggested to characterize the diffusivity of nanoparticles in the ordered network, taking into account both loop stretching and junction deviation effects. The theoretical prediction is in good agreement with numerical simulations and previous theoretical studies.
Article
Nanoscience & Nanotechnology
Hanfeng Zhai, Quan Zhou, Guohui Hu
Summary: Utilizing physical information to improve neural network performance is a promising approach in scientific computing. A modified deep learning framework called BubbleNet is proposed in this study to overcome the difficulty in multiphase flows. Results show that including physical information significantly improves the performance of deep neural networks in predicting flow fields.
Article
Mathematics, Applied
Xinyue Liu, Jinfang Ai, Jun Xie, Guohui Hu
Summary: Gene and macromolecular drug delivery devices based on mechanoporation have attracted increasing attention due to their advantages in biosafety and efficiency. This study proposes a method to apply fluid stress on cells moving in a microchannel under zero-net-mass-flux (ZNMF) jets, allowing cargo transportation through transient pore formation. The immersed finite element method (IFEM) is used to simulate the interaction between cells and fluid fields, investigating cell movement and deformation in this mechanoporation system. By optimizing parameters such as pressure gradient, jet amplitude, and jet frequency, the efficiency of cargo delivery can be improved. Additionally, the stability and safety of the system are analyzed in detail. This research provides valuable insights for designing mechanoporation devices and enhancing drug delivery efficiency.
APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION
(2022)
Article
Mechanics
Yu Lu, Guo-Hui Hu
Summary: In this study, the diffusion of linear polymers in the semi-flexible polymer network inside the cell is investigated using dissipative particle dynamics (DPD). The analysis of Rouse modes reveals that the geometric constraint length N-a plays a crucial role in describing the network effect on polymer diffusion. Based on the analysis of Rouse modes and mean square displacements, a non-dimensional conformational dynamics function dependent on time is proposed, along with a scaling law to predict the long time diffusivity of linear polymers in a semi-flexible polymer network with different mesh sizes.
Article
Physics, Fluids & Plasmas
J. D. Sherwood, S. Ghosal
Summary: This study focuses on the insertion of an elastic rod or fiber into a confined cavity. It is found that most of the fiber lies against the curved interior surface of the cavity, except for the final end section which crosses the interior and ends at the opposite side. The force required for insertion depends on the characteristics of the fiber.
Article
Physics, Multidisciplinary
Ai Jin-Fang, Xie Jun, Hu Guo-Hui
ACTA PHYSICA SINICA
(2020)
Article
Chemistry, Physical
Yu Lu, Guo-Hui Hu
Summary: This study used single-particle Dissipative Particle Dynamics to investigate the diffusion mechanism of nanoparticles in polymer networks, providing insights on the detailed interaction between nanoparticles and polymers. The findings suggest that considering the deformation of the local structure of the polymer network during failed hopping is crucial for accurately predicting the diffusion behavior of nanoparticles in complex environments. The theoretical predictions based on this idea were found to be in good agreement with simulation results, contributing to a deeper understanding of nanoparticle diffusion in diverse research fields.