Latest papers in fluid mechanics

Author(s): Yang Huang, Qing Xiao, and Qiang Zhu

Using large-eddy simulation with overset grids, this work reveals how launch angle shapes the water-exit dynamics of a neutrally buoyant sphere. The sphere exhibits nonlinear velocity attenuation, angle-dependent rotation switching, and systematic lateral deflection driven by shed vortices and image-induced pressure asymmetry. Two exit phases with distinct hydrodynamic signatures are identified. The findings deepen mechanistic understanding of water exit and aid the control of trans-medium bodies.

[Phys. Rev. Fluids 10, 124805] Published Tue Dec 30, 2025

Author(s): Enzo Francisco, Julien Lambret, and Sébastien Aumaître

We present a novel experimental technique based on Diffusing-Wave Spectroscopy that, for the first time, provides high-resolution spatiotemporal maps of energy dissipation at the boundary of a turbulent flow. The flow, generated by an impeller, exhibits Reynolds numbers in the range 1.5×104 to 6×105. Measurements were performed at the boundary of a square container, within a 5×5cm² region at the impeller height. This method enables a direct experimental characterization of the statistical properties of turbulent structures near flow boundaries, offering new insights into boundary-layer dynamics in highly turbulent regimes.

[Phys. Rev. Fluids 10, 124606] Published Mon Dec 29, 2025

Author(s): Hannah M. Clercx and Rudie P. J. Kunnen

We measure the efficiency of convective heat transfer (Nusselt number) by turbulent convection in a rapidly rotating Rayleigh-Bénard convection experiment. Series of measurements are done at two constant values of the Rayleigh number. Using water at different mean temperatures, we change the Prandtl number. Raising the Prandtl number leads to a reduction of the Nusselt number with a significantly stronger dependence than without rotation. We hypothesize that this dependence is caused by the changing ratio of the thermal and kinetic boundary layer thicknesses.

[Phys. Rev. Fluids 10, 123503] Published Fri Dec 26, 2025

Author(s): Debanik Bhattacharjee, Guy Z. Ramon, and Yaniv Edery

Immiscible two-phase flow in porous media occurs in many processes, such as enhanced oil recovery (EOR), as well as oil spill and soil remediation. These processes involve a fluid displacing another immiscible fluid within the confines of a heterogeneous porous structure. The invasion pattern genera…

[Phys. Rev. E 112, 065108] Published Fri Dec 26, 2025

Author(s): Vedant Kumar and Johan Larsson

Two new modeling components for the energy equation in ordinary-differential-equation-based wall-models are proposed in order to improve the accuracy of heat flux predictions in high-speed turbulent boundary layers: a model for the diffusion of turbulence kinetic energy, and an altered near-wall damping of the thermal eddy diffusivity. These modeling additions reduce the a priori error in the heat flux to within 5% across the tested conditions. A decomposition of the a posteriori error shows the presence of two other error sources in wall-modeled large eddy simulations, which are found to contribute up to 5-10% additional error.

[Phys. Rev. Fluids 10, 124605] Published Wed Dec 24, 2025

Author(s): Yasuhide Fukumoto, Satoshi Oshiro, and Taxpulat Ruzi

Streamlines of an exact solution of the Hall-MHD equation for a spherical vortex containing toroidal magnetic flux, wrapped by a vortex sheet. The magnetic tension acts to accelerate the traveling speed of a spherical vortex. The Hall effect, originating from relative fluctuations of electrons and ions, provides further acceleration. Besides, a singular solution specific to Hall-MHD is found for the spherical vortex, which vanishes when the Hall effect is switched off.

[Phys. Rev. Fluids 10, 124703] Published Wed Dec 24, 2025

Author(s): Caroline Cardinale, Steven L. Brunton, and Tim Colonius

Spectral proper orthogonal decomposition (SPOD) finds orthogonal space-time modes that best capture the 2nd order statistics of a data set. However, SPOD is limited to uniform time-resolved data. Many experimental systems are limited by camera speed. Leveraging the relaxed requirement of pairwise data for dynamic mode decomposition (DMD), we propose a pairwise SPOD algorithm that estimates SPOD modes of nonuniformly sampled data. Using 2 PIV setups in tandem, the time delay within a data pair satisfies the Nyquist criterion, but the time between pairs does not, allowing time to process the last snapshot. Computational data is used for validation and the algorithm is of general use.

[Phys. Rev. Fluids 10, 124904] Published Wed Dec 24, 2025

Author(s): L. Moriconi and G. Saisse

Extensive optical measurements of canonical turbulent pipe flows have revealed the existence of structural boundary states (SBSs)—near-wall low-speed streaks strongly correlated with pairs of counter-rotating quasistreamwise vortices. In this study, we investigate the number fluctuations of these st…

[Phys. Rev. E 112, 065106] Published Mon Dec 22, 2025

Author(s): Daniels Krimans, Steven J. Ruuth, and Seth Putterman

Cavitation is a process where bubbles form and collapse within a fluid with dynamic, spatially varying pressure. This phenomenon can concentrate energy density by 12 orders of magnitude, creating light-emitting plasma or damaging nearby surfaces. A key question in cavitation theory and experiments i…

[Phys. Rev. E 112, 065107] Published Mon Dec 22, 2025

Author(s): Fábio S. Bemfica

We present a demonstration of finite-time gradient blow-ups in Israel-Stewart (IS) theories with 1+1D plane symmetry, mathematically showing the existence of smooth initial data that can evolve into shocks across three regimes: pure bulk viscosity, shear viscosity, and diffusion. Through numerical s…

[Phys. Rev. E 112, 065105] Published Fri Dec 19, 2025

Author(s): M. Lebon, Y. Jaunet, J. Sebilleau, and C. Colin

Growth of bubbles nucleated on a wall appear in various industrial applications (gas/liquid contactors, evaporators, hydrogen production), in which their detachment radius is an important parameter for performance optimization. Thanks to gas injection experiments in a shear flow, a force balance model for predicting the detachment radius is built using the relevant forms of the forces extracted from recent literature. A new detachment criterion, based on a maximum advancing contact, allows to determine the receding contact angle and detachment radius with good agreement for both hydrophilic and hydrophobic surfaces.

[Phys. Rev. Fluids 10, 123603] Published Thu Dec 18, 2025

Author(s): Rongfu Guo and Yantao Yang

Basal ice melting under shear flow is a key process in polar and lacustrine environments, where it is influenced by both external forcing and water’s nonlinear equation of state. While previous studies have examined buoyancy-driven convection and shear separately, their interplay with density inversion remains poorly understood. By using direct numerical simulations, we reveal distinct flow regimes and interface morphologies controlled by the inversion stability ratio and effective Richardson number, providing scaling laws for heat transport and a theoretical framework for regime transitions.

[Phys. Rev. Fluids 10, 123502] Published Wed Dec 17, 2025

Author(s): Nishanth Murugan and Anubhab Roy

This work investigates the influence of convective transport within a sedimenting drop on the exit time of a colloidal particle. Using Brownian dynamics simulations, we compute exit times for particles originating from various locations inside the drop over a range of Péclet numbers (Pe). The Péclet…

[Phys. Rev. E 112, 065104] Published Wed Dec 17, 2025

Author(s): R. Benhammadi, A. De Wit, and J. J. Hidalgo

We investigate the impact of permeability heterogeneity on a bimolecular A + B → C reaction that creates a nonmonotonic fluid density profile which can trigger or suppress convective instabilities. The intensity and structure of heterogeneity control how mixing and reaction scale. We find opposing trends for the mixing of reactants and the reaction depending on the media stratification and the density profile. In horizontally stratified media, reaction is hindered by heterogeneity, while in vertically stratified ones it favors reaction. A similar reaction-favoring behavior is also observed for anisotropic multi-Gaussian log-permeability fields.

[Phys. Rev. Fluids 10, 123501] Published Mon Dec 15, 2025

Author(s): Leon L. Ogorodnikov and Sergey S. Vergeles

The pair correlation function of the velocity field is calculated analytically in a rotating three-dimensional coherent turbulent vortex at distances much larger than the scale of wave forcing and below the vortex size. The function demonstrates anisotropic behavior caused by the relatively large shear flow produced by differential rotation in the vortex. The diagonal elements decrease logarithmically with distance in the streamwise direction, and power-like in radial and vertical directions, that manifest upscale energy transfer. The radial-azimuthal component, which turns into the Reynolds stress for zero distance, is short-correlated and is determined by the forcing correlation function.

[Phys. Rev. Fluids 10, 124702] Published Mon Dec 15, 2025

Author(s): Yifeng Yang and Guoxiong Wu

When surface gravity waves propagate through the Marginal Ice Zone, they interact with numerous floating ice floes and affect the evolution of the polar environment. This work develops a method capable of modeling wave interaction with large arrays of arbitrarily shaped ice floes, which remains highly efficient even when the number of floes becomes exceedingly large. The results show how floe geometry and spatial arrangement influence hydrodynamic forces and scattered wave energy, offering new physical insights into realistic wave–ice interactions.

[Phys. Rev. Fluids 10, 124804] Published Fri Dec 12, 2025

Author(s): Yuhang Zeng, Yan Wang, and Shitang Ke

Numerical simulations of gas-liquid-solid (GLS) interactions play a significant role in many essential areas; however, several challenges related to boundary conditions and mass conservation remain. We present a GLS contact condition-enforced immersed boundary method for simulating multiphase flow problems with curved and moving boundaries. This method has been validated by simulating many challenging GLS problems, indicating that it can accurately enforce Dirichlet and Neumann boundary conditions and efficiently restrain nonphysical liquid/mass penetrations near the solid surfaces. The present method is also applied to more complex GLS problems at large density ratios O(103).

[Phys. Rev. Fluids 10, 124903] Published Fri Dec 12, 2025

Author(s): Yiqian Xu, Kai Mu, Ran Qiao, Chengxi Zhao, and Ting Si

Viscoelastic swirling jets hold significant potential for engineering applications, such as atomizers and combustors. This study carries out theoretical analysis and numerical simulations to investigate the role of elasticity in the instability of swirling jets. It is found that the elastic force could suppress jet instability. However, the suppressing effect is weakened as elasticity gradually increases, thereby enhancing the influence of centrifugal force. This results in modes with the higher azimuthal wavenumbers dominating the jet breakup.

[Phys. Rev. Fluids 10, 124002] Published Thu Dec 11, 2025

Author(s): Francesca Pelusi, Andrea Scagliarini, Mauro Sbragaglia, Massimo Bernaschi, and Roberto Benzi

Understanding how emulsions transport heat under buoyancy forcing is essential in many natural and industrial flows, yet the role of interfacial physics remains poorly explored. Using mesoscale lattice Boltzmann simulations, we compare stabilized and non-stabilized liquid–liquid dispersions in Rayleigh–Bénard convection. While their global heat transfer is similar, stabilized emulsions sustain stronger small-scale heat-flux fluctuations, revealing how interfacial stabilization reshapes convective dynamics at the droplet scale.

[Phys. Rev. Fluids 10, 124305] Published Thu Dec 11, 2025

Author(s): Xiaoyue Zhang, Jin Zhang, and Le Fang

Compressible turbulence exhibits complex mechanisms of energy exchange between kinetic and internal modes, yet their dependence on Mach number remains poorly understood. This work investigates two-dimensional compressible Taylor–Green vortex flows and reveals how Mach number governs the pathway of internal-kinetic energy transfer. We identify three stages of energy evolution and derive an analytical model that predicts the initial growth of dilatational kinetic energy. The results provide new insight into compressible-flow energy exchange and inform future turbulence modeling strategies.

[Phys. Rev. Fluids 10, 123401] Published Wed Dec 10, 2025