Latest papers in fluid mechanics

Author(s): Suyog V. Mahulkar and Jaywant H. Arakeri

Flow dynamics of pulse-jetting aquatic animals are often studied with apparatus kept stationary. This paper examines whether the stationary configuration captures the mechanics of the swimming animal. A clapping body, simulating a pulse-jet animal, is tested in freely propelled (dynamic) and forward motion constrained (stationary) conditions. Significant differences are observed in body motion and wake structure: clapping motion is nearly twice as fast in dynamic cases, while mean thrust coefficient and vortex circulation are higher in stationary cases, varying with body depth but which remain constant in dynamic cases. Care is needed in extrapolating data from stationary to swimming bodies.

[Phys. Rev. Fluids 9, 114702] Published Wed Nov 27, 2024

Author(s): Mingxuan Liu (刘明轩) and Elizabeth P. Hicks

We explore how adding a reaction to a Rayleigh-Taylor unstable interface affects the way that two short wavelength modes couple to generate longer wavelength modes. Using simulations, we identify five distinct flame growth solution types. Depending on the greatest common divisor of the wavenumbers of the two modes, the flame may stall, develop coherent pulsations, or even become a metastable traveling wave. We also compare our results with two-mode coupling in ablative and classical Rayleigh-Taylor and show that all three systems may follow the same mode coupling dynamics.

[Phys. Rev. Fluids 9, 113203] Published Tue Nov 26, 2024

Author(s): Ory Schnitzer and Prasun K. Ray

Recent experiments and simulations have suggested that flows of strongly shear-thinning liquids can be greatly enhanced by superhydrophobicity, above and beyond the enhancements familiar for Newtonian liquids. Using asymptotics and numerics, we illuminate the singular mechanism underlying such enhancement, considering the prototypical problem of shear-driven flow over a grooved superhydrophobic surface. A key finding is that the singular scaling of the effective slip length at small solid fractions transitions from logarithmic to algebraic as the viscosity at infinite shear is reduced relative to its value at zero shear.

[Phys. Rev. Fluids 9, L112201] Published Tue Nov 26, 2024

Author(s): Navin Kumar Chandra, Shubham Sharma, Saptarshi Basu, and Aloke Kumar

When liquid droplets encounter high-speed gas flows, they fragment through various modes, with bag-mediated breakup mode observed at lower Weber numbers. This study shows that even minute concentrations of long-chain polymer molecules in a Newtonian solvent can drastically modify its fragmentation characteristics. By investigating the role of liquid elasticity, we uncover how polymeric additives control the fragmentation dynamics of a droplet specifically in the bag breakup regime.

[Phys. Rev. Fluids 9, 113303] Published Mon Nov 25, 2024

Author(s): Yonglu She, Qiang Xu, Tengfei Nie, Xinyi Luo, Mengsha Wang, Xingmiao Ye, Dengwei Jing, and Liejin Guo

The evolution and accumulation of bubbles formed by gas release at the reaction interface present a considerable challenge for improving the efficiency of photoelectrochemical water splitting. Bubble oscillation enhances mass transfer and influences flow dynamics within the system. This study successfully regulates the amplitudes of bubble oscillations by adjusting system temperature and operating voltage and analyzes the mechanism and the mass transfer theory of oscillating bubbles, offering a new approach to managing bubble dynamics.

[Phys. Rev. Fluids 9, 114305] Published Mon Nov 25, 2024

Author(s): Abdelrahman Hassanein, Davide Modesti, Fulvio Scarano, and Woutijn J. Baars

This work provides key insights into the interaction between grazing turbulence and a Helmholtz resonator. By tuning the resonator’s frequency to align with the scales of energetic pressure fluctuations in turbulent boundary layers, the device amplifies small-scale velocity fluctuations while reducing large-scale turbulence energy. This frequency-specific modulation suggests that Helmholtz resonators could serve as scalable, wall-embedded surfaces for targeted turbulence control, offering new pathways in flow control.

[Phys. Rev. Fluids 9, 114610] Published Mon Nov 25, 2024

Author(s): Mahendra K. Verma, Rodion Stepanov, and Alexandre Delache

In this paper, using hydrodynamic entropy, we quantify multiscale disorder in Euler and hydrodynamic turbulence. These examples illustrate that the hydrodynamic entropy is not extensive because it is not proportional to the system size. Consequently, we cannot add hydrodynamic and thermodynamic entr…

[Phys. Rev. E 110, 055106] Published Mon Nov 25, 2024

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

We study one-point statistics of helical turbulent pulsations in the background of a three-dimensional large-scale vortex in a rotating fluid. Assuming that the helical flow is created by a statistically axially symmetric random force with broken mirror symmetry, we analytically calculate the veloci…

[Phys. Rev. E 110, 055107] Published Mon Nov 25, 2024

Author(s): Rui Ni, Kartik V. Bulusu, and Azar Panah

[Phys. Rev. Fluids 9, 110002] Published Fri Nov 22, 2024

Author(s): Chi-Chian Chou, Yuka F. Deki, Ryuta X. Suzuki, Yuichiro Nagatsu, and Ching-Yao Chen

This paper is associated with a poster winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/AP…

[Phys. Rev. Fluids 9, 110502] Published Fri Nov 22, 2024

Author(s): John T. Antolik, Jesse L. Belden, Nathan B. Speirs, and Daniel M. Harris

This paper is associated with a poster winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/AP…

[Phys. Rev. Fluids 9, 110503] Published Fri Nov 22, 2024

Author(s): Marcus Lin, Fauzia Wardani, and Dan Daniel

This paper is associated with a video winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.…

[Phys. Rev. Fluids 9, 110504] Published Fri Nov 22, 2024

Author(s): Chase T. Gabbard, Edward L. Whitesell, and Joshua B. Bostwick

This paper is associated with a poster winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.20…

[Phys. Rev. Fluids 9, 110505] Published Fri Nov 22, 2024

Author(s): Yue Sun, John W. M. Bush, Saverio E. Spagnolie, and Chris H. Rycroft

This paper is associated with a video winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2023…

[Phys. Rev. Fluids 9, 110506] Published Fri Nov 22, 2024

Author(s): David Paulovics, Christophe Raufaste, Thomas Frisch, Cyrille Claudet, and Franck Celestini

This paper is associated with a video winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2023…

[Phys. Rev. Fluids 9, 110507] Published Fri Nov 22, 2024

Author(s): Andre Calado and Elias Balaras

This paper is associated with a poster winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/AP…

[Phys. Rev. Fluids 9, 110508] Published Fri Nov 22, 2024

Author(s): Alexandros Anastasiadis, Annalisa Rossi, Laura Paez, Kamilo Melo, Eric D. Tytell, Auke J. Ijspeert, and Karen Mulleners

This paper is associated with a video winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.…

[Phys. Rev. Fluids 9, 110509] Published Fri Nov 22, 2024

Author(s): Bobae Johnson, Zihan Zhang, Alison Kim, Scott Weady, and Leif Ristroph

This paper is associated with a poster winner of a 2023 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original poster is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.20…

[Phys. Rev. Fluids 9, 110510] Published Fri Nov 22, 2024

Author(s): Lauren Dreier, Tom Marzin, Romain David, Stephane Pienaar, Aman Eujayl, Raphael Vogeley, Yuchen Xi, and P.-T. Brun

This paper is associated with a video winner of the 2023 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.20…

[Phys. Rev. Fluids 9, 110512] Published Fri Nov 22, 2024

Author(s): Evan Pruitt, William Markiewicz, Carlos Gonzalez, and Xiaofeng Liu

This paper is associated with a video winner of a 2023 American Physical Society's Division of Fluids Dynamics (DFD) Gallery of Fluid Motion Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS…

[Phys. Rev. Fluids 9, 110513] Published Fri Nov 22, 2024