Physical Review Fluids

Author(s): Ajay Jangid and Manoranjan Mishra

This study investigates how nonlinear Langmuir adsorption modifies the transport, deformation, and viscous fingering dynamics of a finite miscible solute blob in porous media using a high-resolution Fourier pseudospectral method. The solute’s upstream advection speed decreases with increasing adsorption nonlinearity. The results show that adsorption can suppress or reintroduce viscous fingering, producing lump, comet, and fingered morphologies. Mixing exhibits nonmonotonic behavior at moderate viscosity contrasts, but increases monotonically for larger viscosity contrasts.

[Phys. Rev. Fluids 11, 064002] Published Mon Jun 01, 2026

Author(s): L. Rotily and E. Villermaux

The evaporation dynamics of a stretched spray lamellae is a paradigm for dense sprays evaporation. We consider lamellae made of densely packed micron-sized droplets of liquids with different volatilities, initially in equilibrium with their vapor. We confirm that the lifetime of an individual droplet is much larger than expected from the usual d-squared law for isolated droplets evaporating in a quiescent environment. By analogy with mixing times of scalars, we show that the boundary between the spray and the diluting environment is controlled by the dynamics of its saturating vapor concentration field, explaining the substantial evaporation delay despite the liquid’s division into fine droplets.

[Phys. Rev. Fluids 11, 064501] Published Mon Jun 01, 2026

Author(s): Lukas A. Codispoti, Daniel W. Meyer, and Patrick Jenny

Turbulence accelerates droplet growth in warm clouds, but reliable collision-kernel models remain elusive; and the effect of polydispersity beyond gravitational settling is often not accounted for. We provide a comprehensive map of the bidisperse collision kernel across St ∈ [002_2] and demonstrate that current models systematically overpredict cross-species clustering. We propose a compact parameterization that captures polydisperse collisions across Reynolds numbers, and show that droplet growth is markedly accelerated in highly dissipative parcels—supporting turbulent intermittency as a viable pathway past the warm-rain bottleneck.

[Phys. Rev. Fluids 11, 064601] Published Mon Jun 01, 2026

Author(s): Wilson Lu, Leon Chan, and Andrew Ooi

Despite its geometric symmetry, flow past a highly confined cylinder is known to develop an asymmetric wake. This motivates an examination of the conditions under which this asymmetry is lost. The present results indicate that upstream turbulence can suppress wake bias and restore global symmetry. Turbulence induces early breakdown of the cylinder shear layers immediately after separation, disrupting their coupling with the wall shear layers that would otherwise sustain the asymmetric wake. These results further suggest that any mechanism capable of triggering early breakdown of the cylinder shear layers may likewise promote recovery of global symmetry.

[Phys. Rev. Fluids 11, 064602] Published Mon Jun 01, 2026

Author(s): Ben Steinfurth, Lukas Fuchs, Carolina Cura, Jakob G. R. von Saldern, Kilian Oberleithner, and Julien Weiss

Turbulent separation bubbles are known to exhibit low-frequency “breathing” but its origin remains unclear. This work shows that the dominant long-time dynamics can be captured by a nonlinear Langevin model fitted to Proper Orthogonal Decomposition amplitudes from time-resolved Particle Image Velocimetry. The results reveal bimodal, noise-driven switching between preferred separation states, providing a probabilistic dynamical-systems interpretation of the low-frequency unsteadiness.

[Phys. Rev. Fluids 11, 064603] Published Mon Jun 01, 2026

Author(s): Ahmed Sherif, Jesse Etan Smith, and Leif Ristroph

Light and sound waves can be beamed at molecules or particulates to exert forces, induce motion, and control position. New experiments show that water waves can be used in much the same way at larger scales, and the findings open up new opportunities for action-at-a-distance manipulation. By controlling the shapes of suspended structures, the article shows that they may even be moved sideways or perpendicular to incoming waves. Further, by controlling the form of the wave field, objects can be stably held in place or “tweezed” at a desired location.

[Phys. Rev. Fluids 11, 064801] Published Mon Jun 01, 2026

Author(s): Satoshi Matsumoto, Masanobu Inubushi, and Susumu Goto

We identify the essential role of temporal filtering in enabling data-driven closure models that reproduce turbulent dynamics in the energy-containing range. The scope of the present study differs fundamentally from conventional subgrid-scale modeling, which relies on the universality of small-scale dynamics. While the model constructed on training data preprocessed with a temporal low-pass filter stably and accurately captures the chaotic dynamics of the largest eddies in turbulence, the one trained without temporal low-pass filtering exhibits steady or periodic behavior and fails to capture the chaotic dynamics of the energy-containing range.

[Phys. Rev. Fluids 11, 054606] Published Thu May 28, 2026

Author(s): Daniel Abdulah, Wanying Kang, and Jeremy Rekier

Inertia–gravity waves generated by tidal flow over topography transfer energy and momentum, shaping ocean and atmospheric dynamics. We derive a general solution including non-traditional Coriolis effects, finite depth effects, and non-hydrostatic terms. Non-traditional effects broaden where waves can exist and enhance conversion, especially at low latitudes and given weak stratification. These results expand predictions for dynamics on icy sattelites and other planetary applications.

[Phys. Rev. Fluids 11, 053802] Published Wed May 27, 2026

Author(s): Daniel Abdulah and Wanying Kang

Inertia–gravity waves generated by flow over topography transfer energy and momentum between the ocean and its boundaries. Finite depth forces the wave to be a sum of vertical modes, and when the gravest mode has a length scale comparable to the topographic source, wave conversion and drag are suppressed. We show how a relaxation of the hydrostatic approximation and acoustic approximation influence this suppression.

[Phys. Rev. Fluids 11, 054804] Published Wed May 27, 2026

Author(s): Bal Krishan, Preetika Rastogi, D. Chaitanya Kumar Rao, Niket S. Kaisare, Madivala G. Basavaraj, and Saptarshi Basu

Efficient atomization of multicomponent fuel droplets is central to cleaner and more efficient combustion technologies. This study investigates the bubble-driven breakup of acoustically levitated microemulsion droplets under laser heating, revealing alternative pathways to atomization in stable, practically relevant emulsion fuels. Using high-speed imaging, distinct fragmentation modes are identified that are governed by heating intensity, bubble growth dynamics, and hydrodynamic instabilities, including Faraday and Rayleigh–Taylor mechanisms. The findings provide new physical insight into atomization processes relevant to cleaner combustion and advanced spray technologies.

[Phys. Rev. Fluids 11, 053605] Published Tue May 26, 2026

Author(s): Ory Schnitzer and Ehud Yariv

We show that grooved surfaces fully wetted by a relatively inviscid lubricant may exhibit a large apparent slip length. Exploring this singular limit, we map the key asymptotic regimes defined by the encapsulation height and the submerged ridge area fraction. Our theory bridges classical superhydrophobic models with a newly predicted giant-slip regime. This transition is described by an exterior flow problem where the thin lubricant films wetting the ridges are effectively replaced by a Navier-slip condition.

[Phys. Rev. Fluids 11, 054202] Published Tue May 26, 2026

Author(s): Ya-Ting Jiang, Zi-Mo Liao, Chen-Yue Xie, Peng-Jun-Yi Zhang, Nan-Sheng Liu, and Xi-Yun Lu

Particle-laden turbulence is commonly modeled through two-way coupling, but inter-particle collisions can become significant when inertial particles accumulate near the walls. By comparing the two-way and four-way coupled point-particle direct numerical simulations in channel flow, this work shows that inter-particle collisions can substantially weaken near-wall particle accumulation, enhance turbulence attenuation, and promote drag reduction. These effects arise from the enhanced particle dispersion and the amplified slip-velocity fluctuations, highlighting the importance of four-way coupling for accurately modeling particle-laden turbulent flows.

[Phys. Rev. Fluids 11, 054308] Published Tue May 26, 2026

Author(s): Xianzhang Xu, Daria Skalitzky, and Krishnan Mahesh

Estimating minimum pressure from particle measurements is important for vortex flows, especially when particles are sparse, noisy, or absent near vortex cores. While physics-informed neural networks have been used for flow-field assimilation, their accuracy for minimum-pressure recovery under controlled particle density, particle distribution, incomplete observations, and noise in spatial coordinates and velocity measurements has not been systematically quantified. This work fills that gap using analytical two-/three-dimensional vortices and a turbulent flow of interacting counter-rotating vortices of unequal strength obtained from Large-Eddy Simulations.

[Phys. Rev. Fluids 11, 054604] Published Tue May 26, 2026

Author(s): Shiyi Lu, Anjia Ying, Mengqian Lu, and Lin Fu

An accurate inflow description for atmospheric boundary-layer (ABL) large-eddy simulation (LES) is critical, yet conventional mapping of homogeneous turbulence to inhomogeneous ABLs can distort spatial correlations and disrupt turbulence continuity. In this article, an adaptive energy-preserving mapping (AEPM) strategy is proposed, which preserves target energy profiles while maintaining spatial-correlation properties. An a priori numerical test and three LES cases (neutral/unstable building flows and a flat-plate boundary-layer flow) demonstrate the robustness of the AEPM method and its capability to reproduce realistic inlet and downstream turbulence statistics.

[Phys. Rev. Fluids 11, 054605] Published Tue May 26, 2026

Author(s): Sijie Huang and Jeonglae Kim

Low-frequency unsteadiness (LFU) in separated flows is often linked to drag modulation and recirculation-bubble dynamics, but its governing mechanisms remain unclear. This work introduces a reduced-order, physics-based framework that describes LFU through kinetic-energy transport within the mean recirculation region using vorticity-based quantities derived from the rotational Navier–Stokes equations. For the wake of a normal plate, the analysis reveals that Bernoulli-energy transport and Lamb-vector dynamics govern the charging and discharging processes underlying LFU.

[Phys. Rev. Fluids 11, 054704] Published Tue May 26, 2026

Author(s): Isaak Rubinstein, Gil Himmelhoch, Victor Steinberg, and Boris Zaltzman

We show that the classical Rayleigh–Bénard instability and nonequilibrium electroconvection become strongly intertwined at the limiting current in charge-selective systems. The resulting interaction lowers the instability threshold and removes the short-wave singularity characteristic of electroconvective instability.

[Phys. Rev. Fluids 11, 053703] Published Fri May 22, 2026

Author(s): Basheer A. Khan, Shai Arogeti, Oriel Shoshani, and Alexander Yakhot

Turbulent puffs in pipe flow persist for a prolonged duration before suddenly transitioning to laminar flow via viscous exponential decay. Prior to the onset of relaminarization, the configuration of sectional streamlines indicates the existence of multiple saddles and nodal points near the wall. During relaminarization, they move from the near-wall region and may undergo saddle-node bifurcations that destroy saddle-node pairs. In such cases, the saddle/nodal distance follows the Riccati equation.

[Phys. Rev. Fluids 11, 053902] Published Fri May 22, 2026

Author(s): M. Leonard, D. Maity, N. Vandewalle, and T. Truscott

Stretch an elastic sheet between your hands and let go; it snaps back. Thin water films do the same, rupturing almost as soon as they form. The authors had a simple idea: instead of changing the liquid or coating the surface, just hold the film edges. Two laser-engraved grooves on a plain acrylic plate pin a film of pure water over more than thirty centimeters. When the grooves end, the film ruptures and drips in a steady rhythm. The stability comes not from chemistry, but from geometry.

[Phys. Rev. Fluids 11, 054004] Published Fri May 22, 2026

Author(s): Shiyu Li and Zhixiong Gong

Single-beam acoustic tweezers based on focused ultrasound provide a compact and biocompatible platform for single cell trapping, yet stable three-dimensional trapping is often hindered by acoustic bulk streaming at high frequencies. Here, we develop a unified theoretical– numerical framework to quantify the competition between acoustic radiation force and streaming-induced drag force across viscous-to-inertial flow regimes. We derive pressure-scaling laws for streaming velocity and show trapping performance varies non-monotonically with focal pressure, contrary to conventional expectations. These findings offer practical guidelines for optimizing high-frequency acoustic tweezers for robust cell trapping.

[Phys. Rev. Fluids 11, 054201] Published Fri May 22, 2026

Author(s): Hojun Lee, Itzhak Fouxon, and Changhoon Lee

We report the first direct numerical simulations using a recently introduced exact director-based formulation of the equations of motion for inertial spheroids in turbulence. The results reveal that particle shape and finite inertia induce complex, nonmonotonic trends in preferential clustering. Gravity markedly alters these dynamics, enhancing small-scale clustering for rod- and disk-like particles while suppressing clustering for nearly spherical particles. We confirm that at weak inertia, rod-like spheroids tend to align with the flow’s major stretching direction, whereas disk-like spheroids align with its major shrinking direction.

[Phys. Rev. Fluids 11, 054306] Published Fri May 22, 2026