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1000 results for “fluiddyn”
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Bouncing Indefinitely
On the surface of a gently vibrating liquid, a droplet can bounce indefinitely without coalescing, kept aloft by an air film too small to see. As long as the droplet lifts off before the air layer drains out from under it, the droplet won’t contact the water below. Now scientists have shown that this is possible with a solid surface, too.
Using an atomically smooth mica plate, researchers were able to bounce a droplet indefinitely without wetting the surface. At higher vibration rates (below), the droplet essentially hovers in place, bouncing so quickly that we simply see its shape vibrating in response to the surface. (Image and research credit: L. Molefe et al.; via APS)
#bouncingDroplets #droplets #fluidDynamics #physics #science #vibration -
Hot Droplets Bounce
In the Leidenfrost effect, room-temperature droplets bounce and skitter off a surface much hotter than the drop’s boiling point. With those droplets, a layer of vapor cushions them and insulates them from the hot surface. In today’s study, researchers instead used hot or burning drops (above) and observed how they impact a room-temperature surface. While room-temperature droplets hit and stuck (below), hot and burning droplets bounced (above).
In this case, the cushioning air layer doesn’t come from vaporization. Instead, the bottom of the falling drop cools faster than the rest of it, increasing the local surface tension. That increase in surface tension creates a Marangoni flow that pulls fluid down along the edges of the drop. That flow drags nearby air with it, creating the cushioning layer that lets the drop bounce. In this case, the authors called the phenomenon “self-lubricating bouncing.” (Image and research credit: Y. Liu et al.; via Ars Technica)
#bouncingDroplets #dropletImpact #entrainment #fluidDynamics #marangoniEffect #physics #science
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Hot Droplets Bounce
In the Leidenfrost effect, room-temperature droplets bounce and skitter off a surface much hotter than the drop’s boiling point. With those droplets, a layer of vapor cushions them and insulates them from the hot surface. In today’s study, researchers instead used hot or burning drops (above) and observed how they impact a room-temperature surface. While room-temperature droplets hit and stuck (below), hot and burning droplets bounced (above).
In this case, the cushioning air layer doesn’t come from vaporization. Instead, the bottom of the falling drop cools faster than the rest of it, increasing the local surface tension. That increase in surface tension creates a Marangoni flow that pulls fluid down along the edges of the drop. That flow drags nearby air with it, creating the cushioning layer that lets the drop bounce. In this case, the authors called the phenomenon “self-lubricating bouncing.” (Image and research credit: Y. Liu et al.; via Ars Technica)
#bouncingDroplets #dropletImpact #entrainment #fluidDynamics #marangoniEffect #physics #science
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Hot Droplets Bounce
In the Leidenfrost effect, room-temperature droplets bounce and skitter off a surface much hotter than the drop’s boiling point. With those droplets, a layer of vapor cushions them and insulates them from the hot surface. In today’s study, researchers instead used hot or burning drops (above) and observed how they impact a room-temperature surface. While room-temperature droplets hit and stuck (below), hot and burning droplets bounced (above).
In this case, the cushioning air layer doesn’t come from vaporization. Instead, the bottom of the falling drop cools faster than the rest of it, increasing the local surface tension. That increase in surface tension creates a Marangoni flow that pulls fluid down along the edges of the drop. That flow drags nearby air with it, creating the cushioning layer that lets the drop bounce. In this case, the authors called the phenomenon “self-lubricating bouncing.” (Image and research credit: Y. Liu et al.; via Ars Technica)
#bouncingDroplets #dropletImpact #entrainment #fluidDynamics #marangoniEffect #physics #science
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Hot Droplets Bounce
In the Leidenfrost effect, room-temperature droplets bounce and skitter off a surface much hotter than the drop’s boiling point. With those droplets, a layer of vapor cushions them and insulates them from the hot surface. In today’s study, researchers instead used hot or burning drops (above) and observed how they impact a room-temperature surface. While room-temperature droplets hit and stuck (below), hot and burning droplets bounced (above).
In this case, the cushioning air layer doesn’t come from vaporization. Instead, the bottom of the falling drop cools faster than the rest of it, increasing the local surface tension. That increase in surface tension creates a Marangoni flow that pulls fluid down along the edges of the drop. That flow drags nearby air with it, creating the cushioning layer that lets the drop bounce. In this case, the authors called the phenomenon “self-lubricating bouncing.” (Image and research credit: Y. Liu et al.; via Ars Technica)
#bouncingDroplets #dropletImpact #entrainment #fluidDynamics #marangoniEffect #physics #science
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Hot Droplets Bounce
In the Leidenfrost effect, room-temperature droplets bounce and skitter off a surface much hotter than the drop’s boiling point. With those droplets, a layer of vapor cushions them and insulates them from the hot surface. In today’s study, researchers instead used hot or burning drops (above) and observed how they impact a room-temperature surface. While room-temperature droplets hit and stuck (below), hot and burning droplets bounced (above).
In this case, the cushioning air layer doesn’t come from vaporization. Instead, the bottom of the falling drop cools faster than the rest of it, increasing the local surface tension. That increase in surface tension creates a Marangoni flow that pulls fluid down along the edges of the drop. That flow drags nearby air with it, creating the cushioning layer that lets the drop bounce. In this case, the authors called the phenomenon “self-lubricating bouncing.” (Image and research credit: Y. Liu et al.; via Ars Technica)
#bouncingDroplets #dropletImpact #entrainment #fluidDynamics #marangoniEffect #physics #science
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Mountain ridgelines push oncoming winds up and over their peaks, creating the conditions for some spectacular condensation. If the displaced air is moist enough, it cools and condenses into a cloud that appears to hover over the peak. In reality, winds are constantly moving up and over the mountain, condensing into visible cloud where the temperature is cool enough and then morphing back to water vapor once temperatures increase. This process can create stacked lenticular clouds like those seen here. This spot in New Zealand sees lenticular clouds so often that the formation has its own name: Taieri Pet! (Image credit: satellite image – L. Dauphin, b/w – National Library; via NASA Earth Observatory)
Black-and-white photo of an instance of the Taieri Pet lenticular cloud structure.https://fyfluiddynamics.com/2024/10/lenticular-landscape/
#atmosphericScience #cloudFormation #condensation #fluidDynamics #lenticularClouds #mountains #physics #science #standingWaves
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Mountain ridgelines push oncoming winds up and over their peaks, creating the conditions for some spectacular condensation. If the displaced air is moist enough, it cools and condenses into a cloud that appears to hover over the peak. In reality, winds are constantly moving up and over the mountain, condensing into visible cloud where the temperature is cool enough and then morphing back to water vapor once temperatures increase. This process can create stacked lenticular clouds like those seen here. This spot in New Zealand sees lenticular clouds so often that the formation has its own name: Taieri Pet! (Image credit: satellite image – L. Dauphin, b/w – National Library; via NASA Earth Observatory)
Black-and-white photo of an instance of the Taieri Pet lenticular cloud structure.https://fyfluiddynamics.com/2024/10/lenticular-landscape/
#atmosphericScience #cloudFormation #condensation #fluidDynamics #lenticularClouds #mountains #physics #science #standingWaves
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Tracking Ice Floes
To understand why some sea ice melts and other sea ice survives, researchers tracked millions of floes over decades. This herculean undertaking combined satellite data, weather reports, and buoy data into a database covering nearly 20 years of data. With all of that information, the team could track the changes to specific pieces of ice rather than lumping data into overall averages.
They found that an ice floe’s fate depended strongly on the route it took: ice that slipped from its starting region into warmer, more southern regions was likely to melt. They also saw region-specific effects, like that thick sea ice was more likely to melt in the East Siberian Sea’s summer, possibly due to warmer currents. The comprehensive, fine-grained analyses possible with this ice-tracking technique offer a chance to understand why some Arctic regions are more vulnerable to warming than others. (Image credit: D. Cantelli; research credit: P. Taylor et al.; via Eos)
#climateChange #Eulerian #fluidDynamics #Lagrangian #melting #physics #planetaryScience #science #seaIce
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How Insects Fly in the Rain
Getting caught in the rain is annoying for us but has the potential to be deadly for smaller creatures like insects. So how do they survive a deluge? First, they don’t resist a raindrop, and second, they have the kinds of surfaces water likes to roll or bounce off. The key to this second ability is micro- and nanoscale roughness. Surfaces like butterfly wings, water strider feet, and leaf surfaces contain lots of tiny gaps where air gets caught. Water’s cohesion — its attraction to itself — is large enough that water drops won’t squeeze into these tiny spaces. Instead, like the ball it resembles, a water drop slides or bounces away. (Video and image credit: Be Smart)
#biology #butterfly #cohesion #droplets #fluidDynamics #hydrophobic #insects #physics #science #superhydrophobic #surfaceRoughness #surfaceTension
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Should you flush with toilet lid up or down? Study says it doesn’t matter - Enlarge / Whether the toilet lid is up or down doesn't make much differ... - https://arstechnica.com/?p=2000168 #crosscontamination #fluiddynamics #viralaerosols #epidemiology #toiletplumes #sanitation #bacteria #science #biology #hygiene #toilets
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Branching Dendrites
This award-winning aerial image by photographer Stuart Chape shows a tidal creek in Lake Cakora, New South Wales, Australia. At first glance, it looks much like any river delta, with branching dendritic paths that split into smaller and smaller waterways. That’s deceptive, though, because very different forces shape this creek. Because tides move in and out, a tidal creek is home to flows that move both directions — toward and away from the branches. That also means that flow speeds can change rapidly as the tides shift, which in turn changes which sediments get lifted, dropped, and moved around the creek bed. (Image credit: S. Chape/IAPOTY; via Colossal)
#branchingFlow #fluidDynamics #fluidsAsArt #fractals #geology #geophysics #physics #science #tides
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Update no. 1 from the project: Nearly all important packages were updated with Python 3.14 in the same month /season as the release. Kudos to hardwork from @PierreAugier
https://legi.grenoble-inp.fr/people/Pierre.Augier/fluiddyn-autumn-releases-and-python-314.html
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Triggered by yesterday's discussion about old fluid sims, a short thread with some more examples from that period 2007-2009 to explore fluid dynamics for marbling (well, this one here is more like entering hot "fire" terrain 🥵)...
3/3
#FluidSim #FluidDynamics #Simulation #Marbling #GenerativeArt
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Triggered by yesterday's discussion about old fluid sims, a short thread with some more examples from that period 2007-2009 to explore fluid dynamics for marbling...
2/3
#FluidSim #FluidDynamics #Simulation #Marbling #GenerativeArt
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Triggered by yesterday's discussion about old fluid sims, a short thread with some more examples from that period 2007-2009 to explore fluid dynamics for marbling...
1/3
(cc/ @noah)
#FluidSim #FluidDynamics #Simulation #Marbling #GenerativeArt
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#ThisMonthInFluiddyn - Mar 2024 edition
Happy Easter folks 🐣! We are dropping this a little late.
🔹#FluidImage v0.4.3 is out. Versions 0.4.x contains API changes and new features like a new executor to support Windows, and reworked logs with #Rich progress bars.
https://fluidimage.readthedocs.io/en/latest/changes.html#release-notes
🔹#Transonic v0.6.4 is a bug fix release which works around a #Pythran compilation problem on Windows (in terminals other than Mingw). Related release of #FluidSim and #FluidFFT are out.
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#ThisMonthInFluiddyn - Jan 2024 edition
Plenty on the packaging front this time.
🔹Ported to #pdm as packaging tool for most of our projects.
🔹Trying out #pixi as an alternative to #conda / #mamba. Lock files are great, but we had some hiccups.
🔹#transonic has implemented an experimental support for #meson and #MesonPython. Unreleased and nothing final yet, but tests on #fluidsim and discussion at #Pythran is ongoing.
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#ThisMonthInFluiddyn it is. Let's go 😎
🔹@PierreAugier and friends are finishing up an article, so as a side project they released #formattex and #formatbibtex based on #TexSoup and #BibtexParser
https://pypi.org/project/formattex/
https://pypi.org/project/formatbibtex/> a simple and uncompromising #Latex code formatter
🔹Version 0.7.4 of #fluidsim and fluidsim-core were released containing a refactored energy spectra for #NavierStokes solvers and other bug fixes
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It will be nice to keep you all updated in #FluidDyn (and its projects #transonic, #FluidSim, #FluidLab, #FluidFFT, #FluidImage, #snek5000, #FluidSimFoam ...). Something like
This ___ in FluidDyn
In which frequency would you like to have it?
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On the topic of #CFD solvers, #OpenFOAM is popular choice. We are actively working on creating a new reusable #Python + #FluidSim framework, so that you can define, launch, manage and post-process :blobhaj_plead_1: OpenFOAM simulations from Python :python_logo:
Interesting? Take a look
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Uranus Emits More Than Thought
Since Voyager 2 visited Uranus in 1986, scientists have debated the odd ice giant’s heat balance. The other giant planets of our solar system — Jupiter, Saturn, and Neptune — all emit much more heat than they absorb from the sun, indicating that they have strong internal heat sources. Voyager 2’s measurements from Uranus indicated only weak heat emissions.
But a new study indicates that Uranus does, in fact, have an internal heat source contributing to its heat flux. The study combined observations with a global model of Uranus across the planet’s full 84-year orbit and concluded that Uranus emits 12.5% more internal heat than it absorbs from the sun. That suggests that Uranus may not be so different from its fellow giants, but the planet’s large seasonal variations and differences across hemispheres raise plenty of questions about the planet’s interior structure. (Image credit: NASA; research credit: X. Wang et al.; via Gizmodo)
#fluidDynamics #geophysics #heatTransfer #physics #planetaryScience #science #Uranus
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How Cooling Towers Work
Power plants (and other industrial settings) often need to cool water to control plant temperatures. This usually requires cooling towers like the iconic curved towers seen at nuclear power plants. Towers like these use little to no moving parts — instead relying cleverly on heat transfer, buoyancy, and thermodynamics — to move and cool massive amounts of water. Grady breaks them down in terms of operation, structural engineering, and fluid/thermal dynamics in this Practical Engineering video. Grady’s videos are always great, but I especially love how this one tackles a highly visible piece of infrastructure from multiple engineering perspectives. (Video and image credit: Practical Engineering)
#buoyancy #civilEngineering #convection #engineering #evaporation #fluidDynamics #heatTransfer #infrastructure #physics #science #thermodynamics
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In 1851, George Gabriel Stokes defined a fundamental measure in fluid dynamics, the Reynolds number. #Poetry #Science #History #FluidDynamics #ReynoldsNumber #Stokes (https://sharpgiving.com/thebookofscience/items/p1851b.html)
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How the Edenville Dam Failed
Back in May 2020, the Edenville Dam in Michigan failed dramatically, releasing flood waters that destroyed a downstream dam and caused millions of dollars of damage. In this Practical Engineering video, Grady deconstructs the accident, based on an interim report from the forensic team charged with investigating the failure. Along the way, he explains common causes of dam failures, what made the Edenville failure unusual, and how engineers build modern earthen dams to avoid this older design’s flaws. (Image and video credit: Practical Engineering)
#civilEngineering #damFailure #fluidDynamics #granularMaterial #hydrostaticPressure #physics #science #soilLiquefaction -
How the Edenville Dam Failed
Back in May 2020, the Edenville Dam in Michigan failed dramatically, releasing flood waters that destroyed a downstream dam and caused millions of dollars of damage. In this Practical Engineering video, Grady deconstructs the accident, based on an interim report from the forensic team charged with investigating the failure. Along the way, he explains common causes of dam failures, what made the Edenville failure unusual, and how engineers build modern earthen dams to avoid this older design’s flaws. (Image and video credit: Practical Engineering)
#civilEngineering #damFailure #fluidDynamics #granularMaterial #hydrostaticPressure #physics #science #soilLiquefaction -
How the Edenville Dam Failed
Back in May 2020, the Edenville Dam in Michigan failed dramatically, releasing flood waters that destroyed a downstream dam and caused millions of dollars of damage. In this Practical Engineering video, Grady deconstructs the accident, based on an interim report from the forensic team charged with investigating the failure. Along the way, he explains common causes of dam failures, what made the Edenville failure unusual, and how engineers build modern earthen dams to avoid this older design’s flaws. (Image and video credit: Practical Engineering)
#civilEngineering #damFailure #fluidDynamics #granularMaterial #hydrostaticPressure #physics #science #soilLiquefaction -
How the Edenville Dam Failed
Back in May 2020, the Edenville Dam in Michigan failed dramatically, releasing flood waters that destroyed a downstream dam and caused millions of dollars of damage. In this Practical Engineering video, Grady deconstructs the accident, based on an interim report from the forensic team charged with investigating the failure. Along the way, he explains common causes of dam failures, what made the Edenville failure unusual, and how engineers build modern earthen dams to avoid this older design’s flaws. (Image and video credit: Practical Engineering)
#civilEngineering #damFailure #fluidDynamics #granularMaterial #hydrostaticPressure #physics #science #soilLiquefaction -
The Hydrostatic Paradox
Engineering classes often discuss hydrostatics–the physics of non-moving water–before they cover fluid dynamics and its flows. But hydrostatics is plenty challenging on its own, as Steve Mould demonstrates in this video looking at how hydrostatic pressure depends on depth (and, not, as our intuition might suggest, on shape). As always, he has some nice countertop-scale demos to go with it. (Video and image credit: S. Mould)
#DIYFluids #fluidDynamics #hydrostaticPressure #hydrostatics #physics #science -
The Hydrostatic Paradox
Engineering classes often discuss hydrostatics–the physics of non-moving water–before they cover fluid dynamics and its flows. But hydrostatics is plenty challenging on its own, as Steve Mould demonstrates in this video looking at how hydrostatic pressure depends on depth (and, not, as our intuition might suggest, on shape). As always, he has some nice countertop-scale demos to go with it. (Video and image credit: S. Mould)
#DIYFluids #fluidDynamics #hydrostaticPressure #hydrostatics #physics #science