Physical Review Fluids

Author(s): Jin-bo Cheng, Qi-you Liu, Li-jun Yang, Jun-xue Ren, Hai-bin Tang, Qing-fei Fu, and Luo Xie

Using a needle-plate electro-atomization experimental device, and applying a single pulse disturbance voltage signal, the response of the Taylor cone to a disturbance signal was explored. At the experimental level, the coupling relationship between polarization charge relaxation time and the oscillation period of the Taylor cone was uncovered, revealing the oscillation mechanism of the Taylor cone under this voltage disturbance.

[Phys. Rev. Fluids 9, 013701] Published Mon Jan 08, 2024

Author(s): Z. F. Li, G. X. Wu, and Y. Y. Shi

In the Arctic region, with the reduction of ice extent and thickness, a shipping route may become possible. We theoretically derive the wave motions induced by a point source pulsating and advancing at the marginal ice zone. It is found that when a ship navigates along the edge of an ice sheet, the free surface wave pattern has two V-shaped components. The outer V-wave is very similar to the common free surface wave without the ice sheet, while the inner V-wave is mainly due to the reflection of the outer V-wave by the ice sheet.

[Phys. Rev. Fluids 9, 014801] Published Fri Jan 05, 2024

Author(s): Ian Williams, Patrick B. Warren, Richard P. Sear, and Joseph L. Keddie

In an externally imposed electrolyte (salt) concentration gradient, charged colloids drift at speeds of order one micrometre per second. This phenomenon is known as diffusiophoresis. In systems with multiple salts and “crossed” salt gradients, a nonlocal component of the electric field associated wi…

[Phys. Rev. Fluids 9, 014201] Published Thu Jan 04, 2024

Author(s): Yutaro Fujiki, Hideto Awai, Yutaro Motoori, and Susumu Goto

Deformable elastic particles can accumulate around a vortex center even if the particle is neutrally buoyant. The angle between the deformed particle and the pathline plays important roles in this accumulation process. In this paper, we propose a simple model to explain this interesting accumulation phenomenon.

[Phys. Rev. Fluids 9, 014301] Published Thu Jan 04, 2024

Author(s): Rodolfo Brandão, Gunnar G. Peng, David Saintillan, and Ehud Yariv

Catalytic motors, which self-propel in a liquid due to an inhomogeneous surface reaction, constitute an important illustration of active matter in a non-biological context. Prevailing models of the associated self-diffusiophoretic transport assume a chemical reaction at the boundary of the swimmer. We here address the more realistic scenario where that reaction is balanced by a homogeneous reaction in the bulk. The associated diffusive transport of solute, described by two Damköhler numbers, exhibits a boundary-layer topology which is not encountered in the prevailing models.

[Phys. Rev. Fluids 9, 014001] Published Wed Jan 03, 2024

Author(s): Adam J. K. Yang, Mary-Louise Timmermans, and Gregory A. Lawrence

This study elucidates the regime of fluid instabilities that can arise in a stratified shear flow when density and velocity interfaces are not aligned - a common occurrence in various geophysical flows. Through a combination of linear stability analysis and direct numerical simulations, we unveil a hybrid mode characterized by features of both Kelvin-Helmholtz and Holmboe instabilities. By quantifying the crucial role of asymmetry, our findings contribute to a refined understanding of the dynamics and mixing in these stratified shear flows.

[Phys. Rev. Fluids 9, 014501] Published Tue Jan 02, 2024