New Papers in Fluid Mechanics

Current-vortex-sheet model of the magnetic Rayleigh-Taylor instability

Physical Review E - Tue, 11/05/2024 - 10:00

Author(s): Seunghyeon Baek and Sung-Ik Sohn

This study investigates the Rayleigh-Taylor instability in the magnetic field applied parallel to the interface. The motion of the interface is described using a current-vortex-sheet model. The growth rate of the interface is obtained from a linear stability analysis of the model. The interface of a…


[Phys. Rev. E 110, 055102] Published Tue Nov 05, 2024

Mass transfer in developing flow of a reactive mixture through a curved cylindrical tube

Physical Review E - Mon, 11/04/2024 - 10:00

Author(s): Minyoung Kim and Ali Borhan

Mass transfer to the reactive wall of a curved cylindrical tube is analyzed in the combined entry region where both momentum and concentration boundary layers are developing. The velocity and concentration distributions developing from uniform inlet profiles are obtained using perturbation analysis,…


[Phys. Rev. E 110, 055101] Published Mon Nov 04, 2024

Hydrodynamic fluctuations near a Hopf bifurcation: Stochastic onset of vortex shedding behind a circular cylinder

Physical Review E - Mon, 10/07/2024 - 11:00

Author(s): Ryan M. McMullen and Michael A. Gallis

We investigate hydrodynamic fluctuations in the flow past a circular cylinder near the critical Reynolds number Rec for the onset of vortex shedding. Starting from the fluctuating Navier-Stokes equations, we perform a perturbation expansion around Rec to derive analytical expressions for the statist…


[Phys. Rev. E 110, 045104] Published Mon Oct 07, 2024

Turbulent cascade arrests and the formation of intermediate-scale condensates

Physical Review E - Mon, 10/07/2024 - 11:00

Author(s): Kolluru Venkata Kiran, Dario Vincenzi, and Rahul Pandit

Energy cascades lie at the heart of the dynamics of turbulent flows. In a recent study of turbulence in fluids with odd viscosity X. M. de Wit et al. [Nature (London) 627, 515 (2024)], the two dimensionalization of the flow at small scales leads to the arrest of the energy cascade and selection of a…


[Phys. Rev. E 110, L043101] Published Mon Oct 07, 2024

Enhanced speed of microswimmers adjacent to a rough surface

Physical Review E - Tue, 10/01/2024 - 11:00

Author(s): Deming Nie, Kai Zhang, and Jianzhong Lin

Increased speed is not only the goal of human sports but also the aim we seek to achieve for artificial microswimmers. Microswimmers driven by various power mechanisms have shown unrivaled advantages in drug delivery and cancer therapy. Attaining high mobility with limited power has been a never-end…


[Phys. Rev. E 110, 045101] Published Tue Oct 01, 2024

Anomalous mass diffusion in a binary mixture and Rayleigh-Bénard instability

Physical Review E - Tue, 10/01/2024 - 11:00

Author(s): A. Barletta and B. Straughan

The onset of the Rayleigh-Bénard instability in a horizontal fluid layer is investigated by assuming the fluid as a binary mixture and the concentration buoyancy as the driving force. The focus of this study is on the anomalous diffusion phenomenology emerging when the mean squared displacement of m…


[Phys. Rev. E 110, 045102] Published Tue Oct 01, 2024

Inertia onset in disordered porous media flow

Physical Review E - Tue, 10/01/2024 - 11:00

Author(s): Damian Śnieżek, Sahrish B. Naqvi, and Maciej Matyka

We investigate the onset of the inertial regime in the fluid flow at the pore level in three-dimensional, disordered, highly porous media. We analyze the flow structure in a wide range of Reynolds numbers starting from 0.01 up to 100. We focus on qualitative and quantitative changes that appear with…


[Phys. Rev. E 110, 045103] Published Tue Oct 01, 2024

Two-temperature thermochemical nonequilibrium model based on the coarse-grained treatment of molecular vibrational states

Physical Review E - Mon, 09/30/2024 - 11:00

Author(s): Jiaqi Lv, Qizhen Hong, Xiaoyong Wang, Yifeng Huang, and Quanhua Sun

Although the high-fidelity state-to-state (StS) model accurately describes high-temperature thermochemical nonequilibrium flows, its practical application is hindered by the prohibitively high computational cost. In this paper, we develop a reduced-order model that leverages the widely used two-temp…


[Phys. Rev. E 110, 035107] Published Mon Sep 30, 2024

Mechanism of sinuous and varicose modes in electrokinetic instability

Physical Review E - Fri, 09/27/2024 - 11:00

Author(s): Prateek Gupta and Supreet Singh Bahga

The flow of miscible electrolyte streams with mismatched electrical conductivities in the presence of a parallel applied electric field is known to exhibit electrokinetic instability (EKI). This paper deals with EKI in a configuration where the base state is established by electro-osmotic flow (EOF)…


[Phys. Rev. E 110, 035106] Published Fri Sep 27, 2024

Percolation without trapping: How Ostwald ripening during two-phase displacement in porous media alters capillary pressure and relative permeability

Physical Review E - Thu, 09/26/2024 - 11:00

Author(s): Ademola Isaac Adebimpe, Sajjad Foroughi, Branko Bijeljic, and Martin J. Blunt

Conventional measurements of two-phase flow in porous media often use completely immiscible fluids, or are performed over time scales of days to weeks. If applied to the study of gas storage and recovery, these measurements do not properly account for Ostwald ripening, significantly overestimating t…


[Phys. Rev. E 110, 035105] Published Thu Sep 26, 2024

Long-time emergent dynamics of liquid films undergoing thermocapillary instability

Physical Review E - Thu, 09/05/2024 - 11:00

Author(s): Steven A. Kedda, Michael C. Dallaston, and Scott W. McCue

The study of viscous thin film flow has led to the development of highly nonlinear partial differential equations that model how the evolution of the film height is affected by different forces. We investigate a model of interaction between surface tension and the thermocapillary Marangoni effect, w…


[Phys. Rev. E 110, 035104] Published Thu Sep 05, 2024

Steric effect induces enhancement of electroconvective flow near electrochemical interfaces

Physical Review E - Tue, 09/03/2024 - 11:00

Author(s): Qing Chen, Hehua Zhu, Peng Wang, and Wei Liu

Electroconvection, occurring near electrochemical interfaces, propels the movement of ions and water, leading to intricate phenomena rooted in the fine interplay between fluid, voltage, and ion. Here, neglecting ionic interactions, by incorporating the steric term into the Poisson-Nernst-Planck-Stok…


[Phys. Rev. E 110, 035101] Published Tue Sep 03, 2024

Critical dimension for hydrodynamic turbulence

Physical Review E - Tue, 09/03/2024 - 11:00

Author(s): Mahendra K. Verma

Hydrodynamic turbulence exhibits nonequilibrium behavior with k−5/3 energy spectrum, and equilibrium behavior with kd−1 energy spectrum and zero viscosity, where d is the space dimension. Using recursive renormalization group in Craya-Herring basis, we show that the nonequilibrium solution is valid …


[Phys. Rev. E 110, 035102] Published Tue Sep 03, 2024

From hydrodynamics to dipolar colloids: Modeling complex interactions and self-organization with generalized potentials

Physical Review E - Tue, 09/03/2024 - 11:00

Author(s): T. J. J. M. van Overveld, W. G. Ellenbroek, J. M. Meijer, H. J. H. Clercx, and M. Duran-Matute

The self-organization of clusters of particles is a fundamental phenomenon across various physical systems, including hydrodynamic and colloidal systems. One example is that of dense spherical particles submerged in a viscous fluid and subjected to horizontal oscillations. The interaction of the par…


[Phys. Rev. E 110, 035103] Published Tue Sep 03, 2024

Rebound dynamics of inverse Leidenfrost droplets on dry ice surfaces

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): Yao-Jun Li, Yi-Zhou Liu, Yi-Bo Wang, and Min Chen

The rebound of liquid droplets falling on a hot substrate, known as the Leidenfrost phenomenon, is a well-documented and widely studied topic. However, research on the rebound of droplets on cold surfaces, particularly regarding the inverse Leidenfrost phenomenon, remains relatively limited. In this paper, we experimentally investigate the rebound dynamics of droplets on dry ice surfaces, explore the influencing factors of the inverse Leidenfrost phenomenon, and develop a theoretical model to predict its occurrence.


[Phys. Rev. Fluids 9, 093601] Published Tue Sep 03, 2024

Slip-induced odd viscous flow past a cylinder

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): Ruben Lier

In fluids with broken parity and time-reversal symmetry, odd viscosity introduces the possibility of unique behaviors such as lift force on an obstacle in a symmetric geometry. As incompressible odd viscous fluids are known to not show lift on cylinders under no-slip boundary conditions, this study examines the effect of a finite slip length. While it follows from the Lorentz reciprocal theorem that lift does not arise at first order in slip length, we find that lift does arise at second order upon solving for the fluid profile explicitly. Extending to Oseen flow, we derive a fluid profile that offers new insights into lift force on a cylinder at low Reynolds numbers.


[Phys. Rev. Fluids 9, 094101] Published Tue Sep 03, 2024

Nonequilibrium fluctuations of the direct cascade in surface quasi-geostrophic turbulence

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): V. J. Valadão, T. Ceccotti, G. Boffetta, and S. Musacchio

Turbulence is by definition an out-of-equilibrium phenomenon, with energy flowing continuously from the large, input scales, to the small, dissipative ones. Temporal fluctuations in this energy flux produce corrections to the Kolmogorov energy spectrum which can be predicted using a multiscale perturbative approach. Here we investigate this problem in the Surface Quasi-Geostrophic model of turbulence, comparing the theoretical predictions with the outcome of high-resolution direct numerical simulations.


[Phys. Rev. Fluids 9, 094601] Published Tue Sep 03, 2024

Scaling laws of velocity gradient moments of attached eddies

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): X. X. Li, R. F. Hu, and L. Fang

From Townsend’s attached-eddy model (AEM), the scalings of velocity moments of attached eddies have been widely investigated in literature. We derive analytically the scalings of the moments of velocity gradients of attached eddies by using the AEM, indicating -2 and -3 scalings for second- and third-order moments respectively, which are in agreement with direct numerical simulation (DNS) data. In addition, non-negligible influences of the small-scale eddies on the velocity gradients in the logarithmic region are discussed.


[Phys. Rev. Fluids 9, 094602] Published Tue Sep 03, 2024

Steady-state interfacial gravity waves with one-dimensional class-III triad resonance

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): Jiyang Li, Zeng Liu, Alistair G. L. Borthwick, Jie Cui, and Shijun Liao

Based on the analytic homotopy analysis method, steady-state interfacial waves exhibiting class-III triad resonance are obtained for the first time in a two-layer liquid with a free surface. A parameter study examines the influences of nonlinearity (wave steepness) and upper layer thickness (vertical distance from sea surface to density transition layer) on the amplitudes of wave components, wave spatial profiles, and energy distributions of interfacial waves with multiple resonances.


[Phys. Rev. Fluids 9, 094801] Published Tue Sep 03, 2024

Efficient dynamic mixed subgrid-scale model

Physical Review Fluids - Tue, 09/03/2024 - 11:00

Author(s): Prahladh S. Iyer and Mujeeb R. Malik

Dynamic mixed scale-similarity/Smagorinsky type models (DMM) are promising as they typically have a high a priori correlation with subgrid stresses, and provide sufficient subgrid dissipation to be robust for practical applications. However, past DMMs require two or more levels of test filtering, making them unattractive for production codes. We propose an efficient DMM with a single level of test filtering, and through a posteriori LES tests of turbulent channel flow and wall-modeled LES of turbulent smooth-body separation (see figure, for a Gaussian bump), demonstrate their robustness and improved accuracy with under 5% additional cost compared to the standard Dynamic Smagorinsky Model.


[Phys. Rev. Fluids 9, L092601] Published Tue Sep 03, 2024

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