Physical Review Fluids

Author(s): Ze-Lin Huang, Xi-Li Guo, Jian-Zhao Wu, Bo-Fu Wang, Kai Leong Chong, and Quan Zhou

Vibration has the ability to control the convective heat transport depending on the relative direction of vibration to the gravitation. We show that horizontal vibration (perpendicular to gravitation) enhances heat transport while vertical vibration (parallel to gravitation) suppresses heat transport. The observed heat transport enhancement or suppression is indicated by the critical vibration frequency. We theoretically and numerically reveal the scaling law between the critical vibration frequency and the Rayleigh number.

[Phys. Rev. Fluids 8, 113501] Published Tue Nov 21, 2023

Author(s): Meng Shi and Sigurdur T. Thoroddsen

This paper is associated with a poster winner of a 2022 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 8, 110512] Published Mon Nov 20, 2023

Author(s): Daniele Massaro, Valerio Lupi, Adam Peplinski, and Philipp Schlatter

We explore the global stability of flow in a U-bend (180∘-bend) and compare the results with those in an elbow (90∘-bend) and toroidal pipes. These findings may have relevance for piping systems as well as bends in blood vessels. We identify a Hopf bifurcation at Reb=2528, which is consistent with the elbow flow but significantly lower than the torus, suggesting different underlying transition mechanisms in developing and periodic geometries. In our numerical approach, we utilize a novel method that employs adaptive meshes individually designed for the base flow, direct and adjoint disturbances, optimized for both efficiency and accuracy.

[Phys. Rev. Fluids 8, 113903] Published Mon Nov 20, 2023

Author(s): Marcel M. Louis, Evgeniy Boyko, and Howard A. Stone

Viscosity gradients induced by heating are ubiquitous in three-dimensional printing, oil extraction, heat exchangers, and other applications where viscous flows and temperature fields are coupled. We investigate the influence of wall heating conditions on the pressure drop-flow rate relationship in narrow pipe flows and determine the asymptotic behavior of the pressure drop in both low and high-Peclet number limits.

[Phys. Rev. Fluids 8, 114101] Published Mon Nov 20, 2023

Author(s): Eirik G. Flekkøy, Bjørnar Sandnes, and Knut Jørgen Måløy

Compared with Saffman-Taylor fingers, which result from long-range viscous forces, ‘frictional fingers’ are a distinct hydrodynamic phenomenon that is entirely governed by short range forces. Here we develop a theory that describes the shape of a single frictional finger as a function of the ratio between effective surface tension and friction. The width and shape of the finger are those that minimize the power needed to form them as a balance is established between fluid pressure, capillary, and frictional forces.

[Phys. Rev. Fluids 8, 114302] Published Mon Nov 20, 2023

Author(s): Nicholas T. Wimer, Lucas Esclapez, Nicholas Brunhart-Lupo, Marc Henry de Frahan, Mohammad Rahimi, Malik Hassanaly, Jon Rood, Shashank Yellapantula, Hariswaran Sitaraman, Bruce Perry, Michael Martin, Olga Doronina, Sreejith N. Appukuttan, Martin Rieth, and Marc Day

This paper is associated with a video winner of a 2022 American Physical Societys 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.2022.…

[Phys. Rev. Fluids 8, 110511] Published Fri Nov 17, 2023

Author(s): Juan Li, Alexander Oron, and Youhua Jiang

Droplet impact onto a solid substrate leads to substrate erosion and we find that erosion on a superhydrophobic substrate is mainly caused by droplet retraction and jump-off (the jump-off force), rather than droplet spreading (the inertia-dominated impact force). We measure the jump-off force exerted onto the substrate and attribute it to the sudden horizontal- to-vertical redirection of momentum when the receding droplet squeezes, that is, flow focusing. New scaling models based on the observation of flow focusing are proposed to express the relevant timescale and the magnitude of the jump-off force.

[Phys. Rev. Fluids 8, 113601] Published Fri Nov 17, 2023

Author(s): Franck Plunian and Thierry Alboussière

The spontaneous generation of a magnetic field by the movement of an electrically conducting material is known as the dynamo effect. It occurs in most astrophysical objects, such as the Earth’s core or the Sun’s convection zone. We show that, in liquid metal, the dynamo effect is made possible by the simple rotation of an immersed solid, provided the latter is made of a material with anisotropic electrical conductivity.

[Phys. Rev. Fluids 8, 113702] Published Fri Nov 17, 2023

Author(s): Vitaliy L. Rayz and Sally Bane

[Phys. Rev. Fluids 8, 110001] Published Thu Nov 16, 2023

Author(s): Jian H. Guan, Connor W. Magoon, Matthew Durey, Roberto Camassa, and Pedro J. Sáenz

This paper is associated with a video winner of a 2022 American Physical Society's Division of Fluids 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.202…

[Phys. Rev. Fluids 8, 110501] Published Thu Nov 16, 2023

Author(s): Tuyetthuc Nguyen, Wanjiku Gichigi, and H. C. Mayer

This paper is associated with a video winner of a 2022 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.2022…

[Phys. Rev. Fluids 8, 110502] Published Thu Nov 16, 2023

Author(s): Samuel Boury, Scott Weady, and Leif Ristroph

This paper is associated with a poster winner of a 2022 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 8, 110503] Published Thu Nov 16, 2023

Author(s): Giuseppe Di Labbio, Hamid Ait Abderrahmane, Mohamed Fayed, and Hoi Dick Ng

This paper is associated with a poster winner of a 2022 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 8, 110504] Published Thu Nov 16, 2023

Author(s): Chase T. Gabbard and Joshua B. Bostwick

This paper is associated with a video winner of a 2022 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 8, 110505] Published Thu Nov 16, 2023

Author(s): Bavand Keshavarz and Michela Geri

This paper is associated with a video winner of a 2022 APS/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.DFD.2022.GFM.V0115

[Phys. Rev. Fluids 8, 110506] Published Thu Nov 16, 2023

Author(s): Takumi Matsuzawa, Noah P. Mitchell, Stéphane Perrard, and William T. M. Irvine

This paper is associated with a video winner of a 2022 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 8, 110507] Published Thu Nov 16, 2023

Author(s): Francesco Salvadore, Antonio Memmolo, Davide Modesti, Giacomo Della Posta, and Matteo Bernardini

This paper is associated with a video winner of a 2022 American Physical Society's Division of Fluid Dynamics (DFD) Gallery of Fluid Motion (GFM) 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/10.110…

[Phys. Rev. Fluids 8, 110508] Published Thu Nov 16, 2023

Author(s): Mrudhula Baskaran, Louis Hutin, and Karen Mulleners

This paper is associated with a video winner of a 2022 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 8, 110509] Published Thu Nov 16, 2023

Author(s): D. Panda, L. Kahouadji, L. S. Tuckerman, S. Shin, J. Chergui, D. Juric, and O. K. Matar

This paper is associated with a poster winner of a 2022 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 8, 110510] Published Thu Nov 16, 2023

Author(s): Deepak Prem Ramaswamy, Robin Sebastian, and Anne-Marie Schreyer

Jets-in-supersonic-crossflow (JISCF) have many influential areas of technical applications, amongst them the field of separation control when implemented as air-jet vortex generators. We present results of a combined experiments-numerical work, where we characterize the effects of changing jet-pipe length and jet-exit velocity profiles on the jet-induced structures and the associated separation control effectiveness. The results indicate a strong influence of the state and development of the flow in the pipe on the JISCF field. Consequently, the strength and downstream longevity of streamwise vortices induced by the jets also affect the separation-control effectiveness.

[Phys. Rev. Fluids 8, 113902] Published Thu Nov 16, 2023