Recreating Atmospheres
Researchers built a meter‑scale rotating annular tank that simulates Earth’s equator‑to‑pole temperature gradient by heating the outer rim and cooling a central pipe. Filled with a water‑glycerol mixture, the tank was spun at various rates to observe how energy and vorticity cascade across scales. The measured energy spectrum mirrors real atmospheric data, showing a steep drop at large scales and a flatter tail at smaller scales. Crucially, the cascade intensity changed with temperature, a phenomenon current climate models do not predict.
Bouncing on a Wave
Researchers demonstrated that droplets bouncing on a vertically vibrated fluid surface can pair up in waltz‑like motions when confined in a pressurized chamber that prevents coalescence. The higher air pressure stabilizes the thin air film between droplets, allowing repeated wave‑mediated...
“Sidewall Symphony”
Researchers visualized the turbulent separation bubble that forms over a backward‑facing ramp—an aerodynamic feature common on aircraft—by seeding the flow with helium‑filled soap bubbles. Bright illumination caused each bubble to leave a luminous streak, producing high‑resolution images of the unsteady...
A Colorful Glimpse
In May 2024, satellites captured a striking phytoplankton bloom off Greenland’s coast, stretching hundreds of kilometres and visible from space. The bloom’s vivid blue‑green swirls map the underlying oceanic eddies, acting like natural tracer particles. Researchers highlighted the event as a...
Viscoelastic Vortex Street
Researchers used high‑resolution simulations to examine how a viscoelastic fluid behaves when it flows past a cylindrical obstacle. The study reveals that, beyond the classic von Kármán vortex street, elastic stresses generated by stretched polymers create smaller secondary vortices alongside the...
Understanding Fish and Turbines
Researchers combined real‑world fish trajectory data with Large Eddy Simulation (LES) of an underwater turbine’s wake to pinpoint the hydrodynamic cues fish detect. By mapping fish paths onto simulated turbulence structures, they identified zones that fish avoid or tolerate. The...
A Fungus That Freezes Water
Researchers have identified a protein from the Mortierellaceae fungal family that acts as a powerful ice nucleator, triggering water to freeze at temperatures at least 10 °C higher than normal. The protein appears to have been acquired from bacteria hundreds of...
Shocking Fizzy Jets
Researchers at FY Fluid Dynamics have demonstrated that an effervescent jet— a stream containing both liquid and gas—breaks down into sheets, bags, ligaments and droplets much like a conventional liquid jet, but with a broader size distribution. High‑speed video shows...
Melting Can Propel Icebergs
Researchers have shown that right‑triangular, asymmetric icebergs can self‑propel as they melt. The geometry forces cold, dense meltwater into a sinking plume that generates thrust, reaching roughly 10 % of wind‑driven forces. Experiments confirm the effect in both fresh‑ and salt‑water...
Schooling at Scale
Researchers demonstrated that simple visual and hydrodynamic cues can make digital fish exhibit realistic schooling and milling behaviors. Simulations remain coherent with up to 1,000 agents, but at 50,000 agents the groups fracture into smaller clusters, losing collective order. The...
Scrubbing Bubbles
Researchers at Cornell have demonstrated that low‑frequency sound can energize bubbles in a cleaning bath, causing them to slide in a stop‑and‑go motion along inclined surfaces. This resonant bubble motion boosts cleaning efficacy, achieving up to 90 % cleaner surfaces compared...
Bursting an Oobleck Bubble
Researchers demonstrated that bubbles made from oobleck—a cornstarch‑water suspension—burst differently from soap bubbles. Instead of a smooth circular retraction, the oobleck film tears, fractures, and forms wrinkles as it collapses. Varying the cornstarch mass fraction from 50% to 55% altered...
Fluid Flows Break Up Microswimmer Clumps
Researchers investigating active matter discovered that microswimmers suspended in fluid do not undergo motility‑induced phase separation (MIPS) as dry squirmers do. Using theory and large‑scale simulations, they showed that hydrodynamic interactions generate translational flows that pull swimmers out of nascent...
Bursting Bubbles
Researchers visualized how air bubbles rising through liquid capture dust, viruses, and microplastics, then burst at the surface to launch clouds of microdroplets. By stacking sequential photographs, they traced the bubbles’ ascent and the parabolic arcs of droplets ejected into...
Building Triboelectric Charge
Scientists have demonstrated that tiny carbon contaminants on silica surfaces enable triboelectric charging between identical oxide particles. Using acoustic levitation, a silica bead was repeatedly bounced against a silica plate, and charge accumulation was measured before and after stripping surface...