Article
Mechanics
J. Alaminos-Quesada, J. J. Lawrence, W. Coenen, A. L. Sanchez
Summary: This paper investigates the viscous flow generated by an array of equally spaced identical circular cylinders in an incompressible fluid stream. The study focuses on harmonically oscillating flows with stroke lengths that are comparable to or smaller than the cylinder radius, where the flow remains two-dimensional, time-periodic, and symmetric. The analysis considers the limit of asymptotically small stroke lengths and quantifies the recirculating vortices in the Lagrangian velocity field. The results suggest that the description of the Lagrangian mean flow remains accurate even when the stroke length is comparable to the cylinder radius.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Yonghui Xu, Ivan Delbende, Maurice Rossi
Summary: We present a family of exact equilibrium solutions of the Euler equations consisting of a single helical vortex with an axial flow component. The relations between vorticity, velocity and streamfunction are analytically derived and shown to hold in viscous solutions and become independent of the Reynolds number for sufficiently large values. A procedure to generate a quasi-equilibrium with prescribed characteristics is elaborated and compared with asymptotic theory. It is illustrated how a strong axial flow can jeopardize the evolution towards a quasi-equilibrium.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
O. Erken, F. Romano, J. B. Grotberg, M. Muradoglu
Summary: This study computationally investigates capillary instability in a two-layer liquid film in a rigid tube as a model for liquid plug formation and closure of human airways. Results show that closure occurs more rapidly in the two-layer model compared to a one-layer equivalent, with the serous layer providing effective protection to the airway wall against mechanical stresses.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Idan S. Wallerstein, Uri Keshet
Summary: The study derives the potential flow around a hypersphere using Jansen-Rayleigh expansion, finding that logarithmic terms are essential in three-dimensional objects but absent in two-dimensional objects. It also reveals a connection between the appearance of logarithmic terms and the topological properties of different geometric shapes.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
F. Romano, M. Muradoglu, H. Fujioka, J. B. Grotberg
Summary: This study analyzes the fluid dynamics of lung airway closure and reveals the impact of mucus viscoelasticity on the closure process, resulting in two peaks of wall shear stresses that may lead to lethal or sublethal responses in epithelial cells.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Fluids & Plasmas
James F. Lutsko
Summary: Classical density functional theory is usually formulated in the grand-canonical ensemble, but its application in closed systems has not been systematically studied. This work compares the two ensembles and derives the exact Helmholtz functional for several specific systems, demonstrating the practicality of density functional theory in the canonical ensemble.
Article
Critical Care Medicine
Nicolle J. Domnik, Matthew D. James, Robin E. Scheeren, Grace A. Ayoo, Sarah M. Taylor, Amanda T. Di Luch, Kathryn M. Milne, Sandra G. Vincent, Devin B. Phillips, Amany F. Elbehairy, Sophie J. Crinion, Helen S. Driver, J. Alberto Neder, Denis E. O'Donnell
Summary: Evening dosing of dual, long-acting bronchodilation can improve detailed nocturnal respiratory mechanics and inspiratory neural drive, providing sustained overnight improvements in dynamic respiratory mechanics and inspiratory neural drive compared with placebo.
Article
Mechanics
Zhangming Zeng, Anupam Sharma
Summary: Novel ultrasonic bat deterrents based on aerodynamic whistles are proposed and investigated for their ability to generate ultrasound. Experimental and numerical studies show that the designed deterrents can generate ultrasound with multiple dominant peaks in the designed frequency range.
Article
Mechanics
N. B. Kaye, J. Ogle
Summary: Undergraduate students in fluid mechanics often have misconceptions, which can be challenging to address. This article presents a pedagogical approach using low-cost hands-on activities to correct these misconceptions and improve students' conceptual understanding in introductory engineering fluid mechanics.
Article
Chemistry, Multidisciplinary
Mohamed Badaoui, Grace Kresge, Christopher Ushay, Joel Marthelot, P-T Brun
Summary: Natural materials have highly organized structures and superior properties, motivating the interest in designing biomimetic architected materials. However, the fabrication of such materials, especially soft materials, remains challenging. This study introduces a new frugal methodology that uses capillary-mediated flow to fabricate pixelated soft materials and create complex geometries.
ADVANCED MATERIALS
(2022)
Article
Mechanics
Tianyu Yuan, Wuhan Yuan, Liping Liu, Jerry W. Shan
Summary: This study investigates the anisotropic diffusion of isolated prolate spheroidal particles in the presence of an aligning potential field, revealing the explicit formulas for diffusion coefficients and showing good agreement between theoretical predictions and experimental results. The research provides insights into the coupling between rotation and translation in diffusion processes, as well as ways to control the diffusion of particles with aligning potential fields.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Yashraj Bhosale, Tejaswin Parthasarathy, Mattia Gazzola
Summary: This study investigates the effects of body elasticity on viscous streaming in the case of an immersed soft cylinder. It reveals an additional streaming process that is present even in Stokes flows. The gained insights pave the way for advanced flow manipulation and can be applied to complex geometries beyond circular cylinders.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Charles W. W. Wolgemuth, Jorge I. I. Palos-Chavez
Summary: The dynamics of suspensions of particles has been extensively studied since Einstein's calculation of the leading-order correction to viscosity. In this study, we focus on the low-Reynolds-number behavior of spherical particle suspensions. By deriving a continuum-level description based on the Green's functions for flow, we correct errors in previous derivations and obtain stable equations of motion for particles and fluid. The resulting equations provide accurate predictions for sedimentation speed and viscosity corrections.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Mohammad Nabil, Seyed Amin Nabavizadeh, Paul E. Lammert, Amir Nourhani
Summary: A non-perturbative mesh-free spectral method is proposed in this study for the axisymmetric scenario of a radially highly deformed sphere in Stokes flow. By using spectra of harmonic and biharmonic Stokes flow modes, a general algebraic spectral solution to axisymmetric Stokes flow is provided. The method is demonstrated on two specific problems and compared with the boundary element method, showing good agreement in results.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Sebastian Ziegler, Ana-Suncana Smith
Summary: We propose a versatile perturbative calculation scheme to determine the leading-order correction to the mobility matrix for particles in a low-Reynolds-number fluid with spatially variant viscosity. We demonstrate the application of this scheme to particles in a finite-size, linear viscosity gradient and discuss both symmetric and asymmetric particle placements within this gradient. We find that long-range flow fields with slower decay than their constant-viscosity counterparts exist in fluids with viscosity gradients, and that the self-mobilities and hydrodynamic interaction mobilities of the particles are affected.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Anatomy & Morphology
Sven A. Holcombe, Stewart C. Wang, James B. Grotberg
JOURNAL OF ANATOMY
(2017)
Article
Public, Environmental & Occupational Health
Sven A. Holcombe, Stewart C. Wang, James B. Grotberg
TRAFFIC INJURY PREVENTION
(2017)
Article
Biochemical Research Methods
Mathieu Bottier, Marta Pena Fernandez, Gabriel Pelle, Daniel Isabey, Bruno Louis, James B. Grotberg, Marcel Filoche
PLOS COMPUTATIONAL BIOLOGY
(2017)
Article
Physics, Multidisciplinary
A. D. Araujo, Izael A. Lima, M. P. Almeida, J. B. Grotberg, Jose S. Andrade
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2018)
Article
Physics, Fluids & Plasmas
Parsa Zamankhan, Shuichi Takayama, James B. Grotberg
PHYSICAL REVIEW FLUIDS
(2018)
Article
Mechanics
M. Muradoglu, F. Romano, H. Fujioka, J. B. Grotberg
JOURNAL OF FLUID MECHANICS
(2019)
Article
Physics, Fluids & Plasmas
E. Romano, H. Fujioka, M. Muradoglu, J. B. Grotberg
PHYSICAL REVIEW FLUIDS
(2019)
Article
Biochemical Research Methods
Alireza Kazemi, Bruno Louis, Daniel Isabey, Gary F. Nieman, Louis A. Gatto, Joshua Satalin, Sarah Baker, James B. Grotberg, Marcel Filoche
PLOS COMPUTATIONAL BIOLOGY
(2019)
Article
Mechanics
S. Amir Bahrani, Souria Hamidouche, Masoud Moazzen, Khady Seck, Caroline Duc, Metin Muradoglu, James B. Grotberg, Francesco Romano
Summary: The study investigates the propagation and rupture of mucus plugs in human lungs through experimental injection of synthetic mucus in a pre-wetted capillary tube. The experiments demonstrate the significant impact of the viscoplasticity and viscoelasticity of mucus. A one-dimensional reduced-order model is proposed to explain the experimental evidence, taking into account capillarity and elastoviscoplasticity.
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2022)
Article
Mechanics
Hideki Fujioka, Francesco Romano, Metin Muradoglu, James B. Grotberg
Summary: This study presents a numerical framework for solving the Navier-Stokes equations for liquid plug propagation and split in a three-dimensional bifurcating tube. The presence of transverse gravitational force causes asymmetries in plug splitting and a critical capillary number determines whether the plug splits into two daughter tubes or propagates into the lower daughter tube only.
Article
Engineering, Biomedical
James B. Grotberg, Francesco Romano
Summary: This study presents a microvascular model of fluid transport in the alveolar septa related to pulmonary edema. The model reveals that the interstitial pressures are significantly higher than values used in traditional literature, creating steep gradients and driving fluid towards the lymphatics. This research is of great importance in understanding the function of the pulmonary lymphatic system.
APL BIOENGINEERING
(2022)
Article
Engineering, Biomedical
James B. Grotberg, Francesco Romano
Summary: This study presents a microvascular model of fluid transport in the alveolar septa, including case examples of normal physiology, pulmonary edema, ARDS, hypoalbuminemia, and the effects of PEEP. It highlights the importance of this model for studying COVID-19-induced ARDS and the function of pulmonary lymphatics.
APL BIOENGINEERING
(2023)
Retraction
Engineering, Biomedical
James B. Grotberg, Francesco Romano
APL BIOENGINEERING
(2023)
Review
Engineering, Biomedical
Hannah Viola, Jonathan Chang, Jocelyn R. Grunwell, Louise Hecker, Rabindra Tirouvanziam, James B. Grotberg, Shuichi Takayama
APL BIOENGINEERING
(2019)
Review
Respiratory System
James B. Grotberg
ANNALS OF THE AMERICAN THORACIC SOCIETY
(2019)