Article
Physics, Multidisciplinary
Berta Martinez-Prat, Ricard Alert, Fanlong Meng, Jordi Ignes-Mullol, Jean-Francois Joanny, Jaume Casademunt, Ramin Golestanian, Francesc Sagues
Summary: Experimental results of active nematic fluid show that kinetic energy spectrum follows theoretical predictions at small and intermediate scales, but is influenced by the 3D oil layer at larger scales, leading to the emergence of a new scaling regime. The study reveals that external dissipation plays a significant role in affecting the spectrum properties.
Article
Chemistry, Physical
Sajag Poudel, An Zou, Shalabh C. Maroo
Summary: This study integrates disjoining pressure into continuum simulations and investigates the transpiration process in a 100 m tall tree using these simulations. The findings demonstrate that disjoining pressure can generate high negative pressure in nanopores and sustain high evaporation fluxes.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Mechanics
Jacqueline Mifsud, Duncan A. Lockerby, Yongmann M. Chung, Gordon Jones
Summary: This study investigates the flow disturbance generated by an ultrasonically driven gas bubble confined in a narrow gap, revealing the doubled shear-stress magnitudes during collapse driven by ultrasonic signal and the different collapse regimes identified. The study highlights the differences in physics between acoustically driven bubbles and conventional laser-induced bubbles in experiments.
Article
Multidisciplinary Sciences
Matthew S. E. Peterson, Aparna Baskaran, Michael F. Hagan
Summary: The researchers propose a framework to control shape transformations and filament organization in deformable vesicles, using simulations to reveal various filament spatiotemporal organizations arising from the interplay between active stress and deformability of the confinement. These emerging behaviors have not been observed in traditional systems, providing insights for designing active materials with targeted shape dynamics.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Aleksandr Bashkatov, Syed Sahil Hossain, Gerd Mutschke, Xuegeng Yang, Hannes Rox, Inez M. Weidinger, Kerstin Eckert
Summary: This study investigates the growth of single hydrogen bubbles at micro-electrodes in an acidic electrolyte. New bubble growth regimes are identified and key features such as bubble radius growth law, dynamics of microbubble carpet, onset time of oscillations, and oscillation frequencies are characterized. The system's response to jumps in cathodic potential is also studied, leading to a hypothesis on the mechanisms underlying the microbubble carpet and oscillations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Abhik Basu, Jayanta K. Bhattacharjee
Summary: We analyze the scaling properties of energy spectra in fully developed incompressible turbulence in forced, rotating fluids in 3D. We use scaling arguments to extract scaling exponents that characterize the different scaling regimes of the energy spectra. We speculate on the possibility of two-dimensionalization of 3D rotating turbulence within our scaling theory. Our results can be tested in large-scale simulations and laboratory experiments.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
An Zou, Shalabh C. Maroo
Summary: Molecular dynamics simulations were used to estimate the equilibrium pressure of liquid confined in nanopores. The pressure was found to be highly sensitive to the pore size, with even a small change in size leading to significant shifts from positive to negative values. Additionally, the solid-liquid interaction dominated the pressure in the first liquid layer adjacent to the surface.
Article
Mechanics
Timo Buschhagen, Rohan M. Gejji, Carlo Scalo, Carson D. Slabaugh
Summary: The dynamic response of a confined, premixed turbulent jet flame is investigated at high thermal power densities and turbulence levels. Multiple instability modes were observed, and high-frequency combustion instabilities were found to be associated with the azimuthal hydrodynamic mode of the reactant jet.
Article
Physics, Fluids & Plasmas
Astik Haldar, Abhik Basu
Summary: We elucidate the nature of universal scaling in a class of quenched disordered driven models and explore the intriguing possibility of continuously varying universality classes when coupled with quenched disorders.
Article
Mechanics
Gloire Imani, Lei Zhang, Chao Xu, Munezero Ntibahanana, Hai Sun, Jun Yao
Summary: In this study, direct numerical simulations were conducted to compare the release conditions of finite droplets and long droplets in three-dimensional constrained channels. The results showed that for finite droplets, the maximum pressure increases with the increase in the contact angle, while for long droplets, the maximum pressure is almost the same in water-wet and neutral-wet conditions. The study also found that droplet size affects the release pressure, with the minimum release pressure of finite droplets increasing linearly with the droplet length in water-wet conditions, and the minimum release pressure of long droplets not changing much as the length increases. Furthermore, the release pressure decreases with the increased tapering angle.
Article
Chemistry, Analytical
Zehui Sun, Zhihao Gu, Wei Ma
Summary: Understanding the physicochemical properties of gas molecules in nanobubbles is crucial for chemical and biological processes. In this study, the electrochemical behaviors of single platinum nanoparticles (PtNPs) confined within nanobubbles were successfully monitored. The formation of an oxygen nanobubble on individual PtNPs due to the catalytic decomposition of H2O2 resulted in distinct current traces. The size and gas density of the nanobubbles were quantified using theoretical calculations and high-resolution electrochemical measurements, revealing an ultrahigh oxygen density and gas aggregation behaviors at the nanoscale.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Takahiko Ban, Kohei Matsumoto, Ben Nanzai, Yasushige Mori, Hideki Nabika
Summary: This study systematically varied the wettability of a surfactant-adsorbed solid surface by adjusting the pH of the surrounding fluid and quantitatively investigated the relationship between bifurcation and the spreading coefficient that determines the disjoining pressure. The size-dependent droplet velocity is consistent with a model considering the kinetic factors of relevant chemical reactions. Bifurcation occurred when the sign of the thermodynamically determined dispersive component of the spreading coefficient changed, indicating a change in the direction of the disjoining pressure.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Mechanics
Guillaume T. Bokman, Luc Biasiori-Poulanges, Daniel W. Meyer, Outi Supponen
Summary: Upon interaction with underwater shock waves, bubbles can collapse and produce high-speed liquid jets in the direction of the wave propagation. This work experimentally investigates the impact of laser-induced underwater impulsive shock waves on bubbles of different sizes. The experimental results provide insights into the collapse time and jet speed of bubbles driven by impulsive shock waves as a function of the wave impulse, supporting scaling laws for their behavior.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Chemical
Jingyuan Fei, You Lyu, Xia Zhong, Dianne E. Wiley, Zongwen Liu, Qianhong She
Summary: Limiting flux is a crucial parameter in PRO processes, playing a key role in improving performance. The concentration of dominant scaling precursors in the FS has a significant impact on the stabilized limiting flux. Adjusting FS pH and adding chelating agent can effectively reduce scaling and increase limiting flux.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Chemistry, Physical
Darya Gurina, Ekaterina Odintsova, Andrei Kolesnikov, Mikhail Kiselev, Yury Budkov
Summary: In this study, the behavior of an ionic liquid in carbon nanopores of different widths was investigated using molecular dynamics simulations. The results showed that the confined ionic liquid exhibited a layering structure and displayed charge overcompensation and lattice saturation effects.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Physics, Applied
Shantimoy Kar, Sumit Joshi, Kaustav Chaudhary, Tapas Kumar Maiti, Suman Chakraborty
APPLIED PHYSICS LETTERS
(2015)
Article
Engineering, Chemical
Chandranath Banerjee, Kaustav Chaudhury, Arun Kumar Majumder, Suman Chakraborty
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2015)
Article
Physics, Applied
Kaustav Chaudhury, Shantimoy Kar, Suman Chakraborty
APPLIED PHYSICS LETTERS
(2016)
Article
Mechanics
Uddipta Ghosh, Kaustav Chaudhury, Suman Chakraborty
JOURNAL OF FLUID MECHANICS
(2016)
Article
Engineering, Electrical & Electronic
Ravi Kumar Arun, Nivedita Priyadarshini, Kaustav Chaudhury, Nripen Chanda, Gautam Biswas, Suman Chakraborty
JOURNAL OF MICROMECHANICS AND MICROENGINEERING
(2016)
Article
Computer Science, Interdisciplinary Applications
Hritwick Banerjee, Bibhas Roy, Kaustav Chaudhury, Babji Srinivasan, Suman Chakraborty, Hongliang Ren
MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING
(2019)
Article
Mathematics, Applied
Prakash Harsude, Kethavath Naveen Naik, Kaustav Chaudhury
Summary: This study investigates the impact of spatially distributed wall concentration on the wall-flux of a passive scalar field in a laminar to turbulent transition boundary layer around a flat plate. Numerical simulations using Reynolds averaged transport models were conducted to analyze the distribution of velocity, turbulence, and scalar concentration fields. The research shows that the complex spatial variations in the wall-flux of the passive scalar can be addressed by utilizing Reynolds analogy.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Mechanics
Kaustav Chaudhury, Chandranath Banerjee, Swapnil Urankar
Summary: The systematic approach presented involves analyzing complex eigenvalues of the velocity gradient tensor to extract the characteristic vortex region of a complex flow field. The method is applied to various complex flow scenarios including rotating Rayleigh-Benard convection, turbulent channel flow, and a turbulent flow field in a cylindrical cyclonic separator for assessment.
JOURNAL OF TURBULENCE
(2021)
Article
Mechanics
Chandranath Banerjee, Kaustav Chaudhury, Emmanuel Cid, Florent Bourgeois, Suman Chakraborty, Arun Majumder, Eric Climent
Summary: Tangential introduction of liquid results in a swirling flow within a cylindro-conical hydrocyclone. Through experiments and simulations, we discovered that an air column submerged in the water flow field inside the hydrocyclone exhibits oscillating behavior similar to that of an elastic beam. By establishing a scaling relationship, we obtained a correlation between the wavelength and air-core radius.
Article
Mechanics
Suvechha Hota, Sunil Rout, Kaustav Chaudhury
Summary: This paper presents a swirl chamber with an embedded heating coil that generates swirl flow by tangentially introducing water into a cylindrical chamber, achieving rapid thermal mixing. The experimental observations and theoretical analysis reveal that the asymptotic behavior is due to a near perfect mixing promoted by the stirring ability of the swirling flow. The dispersion model in this scenario conforms to an effective thermal diffusivity that varies linearly with the flow rate.
Article
Mechanics
Adarsh Vasa, Kaustav Chaudhury
Summary: This study analyzes the vortex structures of a mean turbulent flow field in a 90-degree bend pipe. The research reveals the characteristics of turbulence and vortex structures, with the convex contour on the inner side of the bend identified as the key vortex-generating surface. The turbulence induced by vortices dissipates within the bend region, but the vortices transported downstream help generate turbulence to compensate for the loss.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2023)
Article
Mechanics
Anjanee Kumar, Kaustav Chaudhury
Summary: In this article, the author presents an analysis of the flow properties of second order Stokes waves in water. The flow field is described using fixed points and manifolds, which are commonly used for nonlinear dynamic system analysis. It is found that the velocity field components are related by an elliptic correlation, with the fixed points representing the center of the ellipse. The fixed points are observed at the bottom surface, and the vertically oriented manifolds act as guides for flow and straining exchange between the free and bottom surface.
Article
Mechanics
Sunil Rout, Ranjit Kumar Sahoo, Kaustav Chaudhury
Summary: We propose a method and experimental setup for estimating the thermal diffusivities of insulating materials. The setup consists of a boiling water container placed on a heating plate and a test plate placed above it. Both the steady and transient input-response temperature characteristics are measured. By combining experimental observations with theoretical and optimization analyses, we show the potential of using both steady and transient behavior in estimating the thermal diffusivity.
Article
Chemistry, Multidisciplinary
Shantimoy Kar, Aritra Kar, Kaustav Chaudhury, Tapas Kumar Maiti, Suman Chakraborty
Article
Physics, Fluids & Plasmas
Kaustav Chaudhury, Shubhadeep Mandal, Suman Chakraborty