Latest papers in fluid mechanics

Author(s): L. S. Merlo, L. Kadem, W. Saleh, H. D. Ng, and G. Di Labbio

Twin pulsed jets are highly efficient at transferring energy, making them particularly attractive for applications ranging from underwater propulsion and maneuvering to the filling of heart cavities. However, little is known about their dynamic interactions within a hemispherical elastic cavity. Distinct flow regimes are identified here based on formation time and jet spacing. These regimes include short-time decay, decay at the lower wall, wall rebound, and wall rebound with secondary vortices. These findings enhance our understanding of the complex flow patterns generated by certain medical devices and pathological conditions, as well as their effects on cardiac function and performance.

[Phys. Rev. Fluids 11, 054701] Published Mon May 11, 2026

Author(s): Bauyrzhan K. Primkulov

The size of a detaching pendant drop is set by Tate’s law and depends only weakly on the nozzle radius. Here, we show that simple geometric confinement can trigger early detachment at significantly reduced volumes by introducing an additional capillary force. A minimal scaling law collapses the data across geometries, providing a robust and passive route to tune drop size without external actuation.

[Phys. Rev. Fluids 11, L051601] Published Mon May 11, 2026

Author(s): Loïc Tadrist and Tristan Gilet

Walkers (i.e., bouncing droplets coupled to a local Faraday wave) are sent on an orthogonal standing wave. The trajectories of successive walkers form a straight-propagating beam toward the wave that splits into three distinct paths during the interaction with the wave. At the end of the interaction…

[Phys. Rev. E 113, 055104] Published Fri May 08, 2026

Author(s): Ehud Yariv

When the solute concentration is different in the two sides of a semipermeable membrane, solvent flows from the solute-depleted side to the solute-enriched side. More generally, when a vesicle is placed in a solute-concentration gradient, it experiences inward osmosis on the low-concentration side and outward osmosis on the high-concentration side. This paper investigates the resulting motion of the vesicle down the gradient.

[Phys. Rev. Fluids 11, 053603] Published Thu May 07, 2026

Author(s): Demosthenes Kivotides

Quantized vortex filaments in Bose superfluids act as line-like sources for microhydrodynamic (low Reynolds number) normal-fluid motion on scales that standard turbulence grids cannot resolve. We develop a two-level multiscale framework that couples a filtered normal-fluid solver to an explicit microhydrodynamic Stokes Linear Response (LRT), incorporating these effects self-consistently into both vortex dynamics and the resolved normal-fluid equations. The approach enables efficient superfluid-turbulence computations for laboratory, cryogenic, and astrophysical settings.

[Phys. Rev. Fluids 11, 054602] Published Thu May 07, 2026

Author(s): Swapnil Soni and Avishek Ranjan

We derive a new theoretical estimate of the root mean square velocity of the electro-vortex flow (EVF) – a current-driven MHD flow – for high Reynolds number regime using an inertia-Lorentz balance in the vorticity transport equation. This estimate accounts for the dimension of the current collector, an important parameter that governs the EVF. There is an excellent agreement between the theory and numerical simulations performed using the custom-built code in OpenFOAM. We also explain the EVF characteristics using these results. Our numerical results reveal a distinct flow feature stemming from the domain finiteness at relatively higher current collector radii.

[Phys. Rev. Fluids 11, 053701] Published Wed May 06, 2026

Author(s): W.-P. Breugem and Y. E. Kamis

We investigated the dynamics of a Newtonian liquid jet issued from a long circular nozzle into a gaseous environment. While the jet contracts at high Reynolds number, it swells at low Reynolds number. To analyze this, we derived an integral momentum balance for the flow in both the nozzle and jet. The swell at low Reynolds number is associated with an excess integral wall shear stress near nozzle exit relative to perfect Poiseuille flow. Numerical simulations revealed self-similar behavior of the flow within the nozzle, which is explained from the stick-slip transition at the nozzle lip and the subsequent development of a boundary layer along the jet interface.

[Phys. Rev. Fluids 11, 054101] Published Wed May 06, 2026

Author(s): Morie Koseki and Marco Edoardo Rosti

This study investigates the effect of compliant walls on the turbulent heat transfer in channel flows over viscous-hyperelastic walls. We show that the compliant wall leads to an increase not only of the momentum transfer but also of the heat transfer, and that the heat transfer enhancement is favorable compared to the momentum one

[Phys. Rev. Fluids 11, 054301] Published Wed May 06, 2026

Author(s): Pabitra Badhuk, Atanu Dolai, and R. V. Ravikrishna

Twin-swirl flows can generate various vortex breakdown structures depending on the swirling direction, strength, and the momentum ratio between the swirling streams. The present study uses scale-resolving simulations to analyze the mechanism of radial pressure gradient formation, role of entrainment in mixing, and identification of coherent structures in such flows. We show that while the centripetal acceleration dominates the radial pressure gradient formation with a single swirler, the contribution of advection and turbulence components are also significant in twin-swirl flows. We also show that the entrainment velocity is better estimated by the rms components than the mean velocity.

[Phys. Rev. Fluids 11, 054601] Published Wed May 06, 2026

Author(s): A. Roccon, G. Amati, L. Brandt, D. Calhoun, P. Costa, W. Lu, S. Pirozzoli, D. Richter, M. Umair, D. You, T. Zahtila, and C. Marchioli

[Phys. Rev. Fluids 11, 059901] Published Wed May 06, 2026

Author(s): Chapnik Zvi and Or Yizhar

Micronanorobotic swimmers have promising potential for future biomedical tasks such as targeted drug delivery and minimally invasive diagnosis. An efficient method for controlled actuation of such nanoswimmers is applying a rotating external magnetic field, resulting in helical corkscrewlike locomot…

[Phys. Rev. E 113, 055103] Published Wed May 06, 2026

Author(s): Yuxing Jiao and Mingcheng Yang

A fluid with broken time-reversal symmetry would exhibit odd transport coefficients, such as odd viscosity, thermal conductivity, and diffusion coefficient, which may fundamentally alter the fluid properties and significantly influence the structure and dynamics of immersed objects. Here, we develop…

[Phys. Rev. E 113, 055102] Published Tue May 05, 2026

Author(s): Naresh K. Dhanwani, Ajay Harishankar Kumar, Hansol Wee, and Osman A. Basaran

Using theory and simulation we analyze the retraction of a highly slender Newtonian liquid sheet with surface covered by a surfactant monolayer surrounded by air primarily in the Stokes limit with 1/Oh=0 where Oh is the Ohnesorge number. As the two surfaces of the sheet remain planar for long times after retraction is initiated, a control volume analysis is used to analytically calculate the maximum film thickness and retraction velocity. The role of finite inertia is also studied and it is shown that rim formation is suppressed if Oh (1+B0Γ0)≫L0 where B0 and L0 are the Boussinesq-Scriven number and initial sheet aspect ratio and Γ0 the initial surfactant concentration.

[Phys. Rev. Fluids 11, 053602] Published Mon May 04, 2026

Author(s): Wilfried Raffi, Jochem G. Meijer, and Detlef Lohse

Freeze–thaw cycles drive complex interactions between objects and moving solid–liquid interfaces. Using experimental model systems of oil-in-water emulsions and polystyrene particle suspensions, we reveal the occurence of hysteresis: Solid particles drift from their initial positions after one freeze-thaw cycle, while deformable oil droplets largely return to their initial positions with reversible shape changes. Our theoretical model captures these trends, highlighting the complexity of freeze–thaw dynamics.

[Phys. Rev. Fluids 11, 054001] Published Mon May 04, 2026

Author(s): Brandon Choi, Matteo Ugliotti, Mateo Reynoso, Daniel R. Gurevich, and Roman O. Grigoriev

This paper introduces a data-driven framework for constructing accurate and general equivariant models of multiscale phenomena which does not rely on specific assumptions about the underlying physics. This framework is illustrated using incompressible fluid turbulence as an example that is represent…

[Phys. Rev. E 113, 055101] Published Mon May 04, 2026

Author(s): Yuehongjiang Yu, Yang Yang, Jie Qi, Yu Qiu, Mengdi Sun, and Ke Xu

Bubble dissolution in porous media controls key applications including geological carbon sequestration, groundwater remediation, and energy engineering. The classic Epstein-Plesset model for bubble dissolution in open space is invalid in porous medium. We reveal how porous structure fundamentally reshapes dissolution, and derive analytical solutions for three typical bubble morphologies (single-pore, strip-shaped, and block-shaped). Analytical solutions are well verified by experiments and numerical simulations. Our new theory offers critical theoretical support for optimizing subsurface gas storage and gaseous pollutant removal technologies.

[Phys. Rev. Fluids 11, 053601] Published Fri May 01, 2026

Author(s): Xun Sun (孙逊), Zhizhong Zhou (周智忠), Weibin You (游炜彬), Sivakumar Manickam, Yunqiao Liu (刘筠乔), Wenlong Wang (王文龙), and Benlong Wang (王本龙)

We show that the incompressible Large eddy simulations of the condensation fronts (also referred to as bubbly shocks or condensation shocks) in partial cavitation within a three-dimensional Venturi agree well with the experiments. The condensation front is fundamentally different from traditional shock waves. The density variations due to evaporation and condensation of cavitation, rather than fluid compressibility, govern its formation and propagation. Hence, a compressible solver is unnecessary for simulating condensation fronts. These findings offer a new understanding of the shedding mechanism of partial cavitation.

[Phys. Rev. Fluids 11, 044304] Published Thu Apr 30, 2026

Author(s): Yutaro Motoori, Hideki Murahata, and Susumu Goto

We numerically investigate the swimming mechanism of a dolphin by focusing on the hierarchy of vortices in its turbulent wake. Using direct numerical simulations of a self-propelled dolphin and scale decomposition of the flow, we show that the caudal fin generates large vortex rings that contribute most of propulsion, whereas smaller vortices are created through the energy cascade but contribute little to propulsion. We also show that this mechanism remains robust regardless of the Reynolds number.

[Phys. Rev. Fluids 11, L042601] Published Thu Apr 30, 2026

Author(s): Bidisha Bhatt and Andreas Carlson

A droplet adopts a complex shape in a spring and can create significant spring compression, potentially functioning as a capillary weight-lifting system. By tuning the ratio between the pitch of the soft spring and the droplet size reveals a range of distinct droplet flow regimes, in which the vertical velocity is directly linked to the droplet’s rotational motion. Active control of the spring’s extension and compression demonstrates how both the static and dynamic states of the droplet can be controlled.

[Phys. Rev. Fluids 11, 043607] Published Wed Apr 29, 2026

Author(s): Chian Yeh Goh and Guillaume Blanquart

We revisit a largely overlooked theoretical model from Belen’kii and Fradkin (1965) and show that it captures many key features of non-Boussinesq Rayleigh-Taylor mixing observed in modern studies. By extending the analysis of this pioneering study, we uncover new physical insight and develop a practical, analytically tractable representation. Calibrated with DNS data, this work bridges classical theory and modern turbulence modeling, offering a compact tool for understanding and predicting variable-density turbulent flows.

[Phys. Rev. Fluids 11, 044501] Published Wed Apr 29, 2026