This month, CTCS (IIT Madras) & @PIK_climate present a webinar
📢: On the absence of the ultimate regime in turbulent thermal convection
🎙️: Prof. Mahendra Verma, IIT Kanpur
📅: May 25 |⏰19:30 IST | 16:00 CEST | 10:00 EDT
🔗: https://us06web.zoom.us/webinar/register/WN_K4F5k9O4QmuZbt5uZNj9Qw

#ComplexSystems #webinarinvite #Zoomcodes #IITMadras #IITK #PIK #Nonlineardynamics #Turbulence #BoundaryLayer #FluidDynamics #Bifurcations #FluidMechanics #HeatTransfer #Convection #Scaling

Seeing Stress in an Avalanche

Researchers sometimes study avalanches and other granular flows in a rolling drum, where grains can cascade down continuously. Here, the twist is that they’ve done it with photoelastic disks, which show stress patterns when viewed under crossed polarizing filters.

In any given moment, the contacts between neighboring particles form a force chain that lights up the disks. In motion, the effect resembles lightning forking and branching across the sky. The close-ups of stress reverberating during impact are especially mesmerizing. (Video and image credit: R. Hodgson et al.)

A new AI approach, trained on physical equations, allows identifying the moment when a stable flow becomes unstable.

Machine learning could transform simulations in engineering, weather, and extreme events.

🔗 https://phys.org/news/2026-04-ai-method-flags-fluid-simulations.html

#FluidDynamics #MachineLearning #ComputationalPhysics #Bifurcation #leidenfrost

A useful reminder in fluid mechanics: maximizing velocity is not the same as maximizing momentum or energy transfer. This paper explores how global mass balance constrains synthetic jet actuator performance.

🔗 https://doi.org/10.1063/5.0326035

#FluidDynamics #Physics #FlowControl #SyntheticJets #NonlinearDynamics

Jets From Impact

When a test tube of liquid hits a surface, the curvature of the meniscus focuses the rebounding fluid into a jet. In this video, researchers show some of the many variations they’ve explored on these experiments–from changing the depth of the fluid and the shape of the container, to changing the working fluid to honey or to dry grains. It’s a nice introduction to a fascinating phenomenon! (Video and image credit: H. Watanabe et al.; research credit: H. Watanabe et al. and K. Kobayashi et al.)

📄 Study Review

Basic Science and Pathogenesis

Deep belly breathing increases fluid movement between the brain and spine by 56% compared to normal breathing. The shift in brain blood flow also increases by 41%. Fluid exchange between head and spine is 10 times larger than within the brain.
Study type: Observational

#Neuroscience #Breathing #FluidDynamics

https://s.fitbodyscience.com/2eqB5Y

Liquid Pulleys and Gears

In mechanical systems, gears and pulleys transmit rotation from one location to another. Here, researchers explore a fluid dynamical version of such systems. The set-up consists of two rotors contained in a cylindrical corral filled with a water-glycerin mixture. One of the rotors is active, marked here with orange; the other (blue) one is passive, meaning that it can rotate due to the forces on it but it is not actively driven by a motor.

The three flow visualizations illustrate different configurations the rotors can take on, depending on their separation distance. In the top image, the rotors have a moderate separation distance and the passive one rotates opposite of the active one. That rotation direction is set by the high-shear flow on its inner side. If the rotors are close together (left image), they rotate in the same direction, aided by strong shear on the outside edge of the passive rotor; this mimics being linked with a belt. And, finally, if the rotors are widely separated, they also corotate, with the fluid in between acting like a virtual gear linking them. (Image credit: J. Smith et al.)

“Spiralling Textures”

Wet fur forms a spiral of spiky hairs in this image by photographer Ben Dalgleish. For thin and flexible fibers like hair, a little moisture lets them clump together, forming stiffer (but still flexible) shapes. The technical term for this water-meets-flexible-solid phenomenon is elastocapillarity, and it lets you do things like wind a wire with a bubble. It also makes a big difference when washing hair, including in space. (Image credit: B. Dalgleish/BWPA; via Colossal)