年度推荐 | JFM Rapids2024年度精选论文

A scaling law for the length of granular jumps down smooth inclines

Andrés Escobar, François Guillard, Itai Einav and Thierry Faug

Elisabeth Guazzelli: “This paper presents the results of extensive two- and three-dimensional discrete element method (DEM) simulations of granular standing jumps and proposes a scaling law for the length of the jumps. Granular jumps commonly occur during granular flows over complex topographies or when hitting retaining structures and are of immense practical importance. The physics reported is new and interesting, and the results are particularly relevant to the design of safer avalanche retaining structures and various equivalent structures for other types of flows.”

Heat transfer in a quasi-one-dimensional Rayleigh–Bénard convection cell

Lu Zhang and Ke-Qing Xia

Detlef Lohse: “This paper sheds fresh light on a classical problem in fluid dynamics – Rayleigh-Bénard convection – but now in an important but often overlooked parameter regime: that one of very small aspect ratios (slender cells), where the side walls strongly stabilize the flow. By ingenious and carefully performed experiments and accompanying numerical simulations the flow physics in such cells beyond onset of convection and in the turbulent regime is revealed – a clear case for a JFM Rapids.”

Data-driven nonlinear turbulent flow scaling with Buckingham Pi variables

Kai Fukami, Susumu Goto and Kunihiko Taira

Dan Henningson: “This paper uses data-driven regression to learn nondimensional pi groups from data. The authors apply it to a challenging example in decaying isotropic turbulence. These data-driven methods are timely, and this work is refreshing in that they are learning something that has deep physical interpretation. Many machine learning techniques today give limited new physical insights. This work will provide fluids researchers with powerful tools to analyze complex flows.”

Spontaneous locomotion of a symmetric squirmer

Aditya Khair and Ory Schnitzer

Sarah Waters:  “This fascinating numerical study considers the spontaneous locomotion of a symmetric spherical squirmer.   The authors impose a front-back symmetric slip velocity distribution on the sphere surface, and demonstrate that some squirmers can spontaneously self-propel above a critical Re.  This is a very interesting and exciting study that offers a potential mechanism for locomotion of moderate-Reynolds-number microorganisms.