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1000 results for “fluiddyn”
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Ice Without Gravity
Astronaut Don Pettit is back in space, and that means lots of awesome microgravity experiments. Here, he grew thin wafers of ice in microgravity in a -95 degree Celsius freezer. Then he took the ice wafers and photographed them between crossed polarizers, creating this colorful image. The colors highlight different crystal orientations within the ice and give us a hint about how the freezing front formed and expanded. I can’t wait to see more examples! (Image credit: D. Pettit/NASA; via Ars Technica; submitted by J. Shoer)
#astronaut #crystalGrowth #fluidDynamics #fluidsAsArt #iceFormation #microgravity #physics #polarizedLight #science
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Ice Without Gravity
Astronaut Don Pettit is back in space, and that means lots of awesome microgravity experiments. Here, he grew thin wafers of ice in microgravity in a -95 degree Celsius freezer. Then he took the ice wafers and photographed them between crossed polarizers, creating this colorful image. The colors highlight different crystal orientations within the ice and give us a hint about how the freezing front formed and expanded. I can’t wait to see more examples! (Image credit: D. Pettit/NASA; via Ars Technica; submitted by J. Shoer)
#astronaut #crystalGrowth #fluidDynamics #fluidsAsArt #iceFormation #microgravity #physics #polarizedLight #science
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Herding Sheep
Flocks of birds, schools of fish, and herds of sheep all resemble fluids at times, and physicists have been trying to recreate their collective motion for decades. Many of these models simplify the animals into particles that follow simple rules based on the direction and speed of their neighbors. Over time, the models have grown more complex; for example, some might differentiate a “sheepdog” particle from “sheep” particles. And some models even tweak the “sheep” to account for the personality traits that real sheep show, like how skittish they behave toward a sheepdog. Physics World has a neat overview of several studies in this vein. (Image credit: E. Osmanoglu; via Physics World)
#collectiveMotion #flocking #fluidDynamics #physics #schooling #science #sheep
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Herding Sheep
Flocks of birds, schools of fish, and herds of sheep all resemble fluids at times, and physicists have been trying to recreate their collective motion for decades. Many of these models simplify the animals into particles that follow simple rules based on the direction and speed of their neighbors. Over time, the models have grown more complex; for example, some might differentiate a “sheepdog” particle from “sheep” particles. And some models even tweak the “sheep” to account for the personality traits that real sheep show, like how skittish they behave toward a sheepdog. Physics World has a neat overview of several studies in this vein. (Image credit: E. Osmanoglu; via Physics World)
#collectiveMotion #flocking #fluidDynamics #physics #schooling #science #sheep
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Herding Sheep
Flocks of birds, schools of fish, and herds of sheep all resemble fluids at times, and physicists have been trying to recreate their collective motion for decades. Many of these models simplify the animals into particles that follow simple rules based on the direction and speed of their neighbors. Over time, the models have grown more complex; for example, some might differentiate a “sheepdog” particle from “sheep” particles. And some models even tweak the “sheep” to account for the personality traits that real sheep show, like how skittish they behave toward a sheepdog. Physics World has a neat overview of several studies in this vein. (Image credit: E. Osmanoglu; via Physics World)
#collectiveMotion #flocking #fluidDynamics #physics #schooling #science #sheep
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Humans spend a lot of time moving in crowds. Matthew R. Francis and Maki Naro collaborate on this comic for @KnowableMag, which demonstrates how tools from fluid dynamics can help model crowd behavior and smooth the flow of crowds, potentially making us safer.
#Science #Physics #FluidDynamics #CrowdBehavior #ThinkingFluids #Newstodon #NewstodonFriday #FollowFriday
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Humans spend a lot of time moving in crowds. Matthew R. Francis and Maki Naro collaborate on this comic for @KnowableMag, which demonstrates how tools from fluid dynamics can help model crowd behavior and smooth the flow of crowds, potentially making us safer.
#Science #Physics #FluidDynamics #CrowdBehavior #ThinkingFluids #Newstodon #NewstodonFriday #FollowFriday
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Humans spend a lot of time moving in crowds. Matthew R. Francis and Maki Naro collaborate on this comic for @KnowableMag, which demonstrates how tools from fluid dynamics can help model crowd behavior and smooth the flow of crowds, potentially making us safer.
#Science #Physics #FluidDynamics #CrowdBehavior #ThinkingFluids #Newstodon #NewstodonFriday #FollowFriday
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Humans spend a lot of time moving in crowds. Matthew R. Francis and Maki Naro collaborate on this comic for @KnowableMag, which demonstrates how tools from fluid dynamics can help model crowd behavior and smooth the flow of crowds, potentially making us safer.
#Science #Physics #FluidDynamics #CrowdBehavior #ThinkingFluids #Newstodon #NewstodonFriday #FollowFriday
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Many industrial processes, including those producing aluminum and “green” hydrogen, use electrodes to speed up chemical reactions. Unfortunately, bubbles that form on the electrode reduce its efficiency anywhere from 10 to 25 percent by blocking parts of the electrode. The assumption has been that any area shadowed by bubbles is blocked, but a recent study shows that’s not the case. Instead, it’s only the electrode area in direct contact with the bubble that’s blocked.
To show this, researchers looked at a smooth electrode where bubbles formed randomly (left) and a nanotextured one with many spots where bubbles could form (right). In the animation above, bubble shadows are highlighted with circles. There are clearly more bubbles on the nanotextured electrode, but it actually performs better than the smooth electrode because the bubble contact area is smaller. (Image and research credit: J. Lake et al.; via MIT News)
https://fyfluiddynamics.com/2024/11/blocking-bubbles/
#bubbles #chemistry #fluidDynamics #nanoscale #nucleation #physics #science #surfaceRoughness
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Many industrial processes, including those producing aluminum and “green” hydrogen, use electrodes to speed up chemical reactions. Unfortunately, bubbles that form on the electrode reduce its efficiency anywhere from 10 to 25 percent by blocking parts of the electrode. The assumption has been that any area shadowed by bubbles is blocked, but a recent study shows that’s not the case. Instead, it’s only the electrode area in direct contact with the bubble that’s blocked.
To show this, researchers looked at a smooth electrode where bubbles formed randomly (left) and a nanotextured one with many spots where bubbles could form (right). In the animation above, bubble shadows are highlighted with circles. There are clearly more bubbles on the nanotextured electrode, but it actually performs better than the smooth electrode because the bubble contact area is smaller. (Image and research credit: J. Lake et al.; via MIT News)
https://fyfluiddynamics.com/2024/11/blocking-bubbles/
#bubbles #chemistry #fluidDynamics #nanoscale #nucleation #physics #science #surfaceRoughness
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Many industrial processes, including those producing aluminum and “green” hydrogen, use electrodes to speed up chemical reactions. Unfortunately, bubbles that form on the electrode reduce its efficiency anywhere from 10 to 25 percent by blocking parts of the electrode. The assumption has been that any area shadowed by bubbles is blocked, but a recent study shows that’s not the case. Instead, it’s only the electrode area in direct contact with the bubble that’s blocked.
To show this, researchers looked at a smooth electrode where bubbles formed randomly (left) and a nanotextured one with many spots where bubbles could form (right). In the animation above, bubble shadows are highlighted with circles. There are clearly more bubbles on the nanotextured electrode, but it actually performs better than the smooth electrode because the bubble contact area is smaller. (Image and research credit: J. Lake et al.; via MIT News)
https://fyfluiddynamics.com/2024/11/blocking-bubbles/
#bubbles #chemistry #fluidDynamics #nanoscale #nucleation #physics #science #surfaceRoughness
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Even freshwater contains trace salts and minerals that cause scaly buildups as they evaporate. Getting rid of the scale usually requires toxic chemicals and/or lots of scrubbing, neither of which are desirable at the industrial level. At the same time, we’re extremely limited in the amount of freshwater that we have available; only about 1% of Earth’s water is liquid and fresh. If we could use salt water in more industrial processes, that would preserve freshwater for drinking and agriculture. But how do we tackle the scaly buildup?
(A) On microtextured surfaces, salt from evaporating drops can work its way into the gaps, destroying the superhydrophobicity of the surface. (B) In contrast, nanotextured surfaces give the salt nowhere to adhere, resulting in “salt critters” that grow upward and detach.Enter “salt critters.” Researchers found that when salt water evaporated from microtextured surfaces designed to shed water, salt would eventually build up in the gaps, breaking the hydrophobic effect and allowing scale to build up. In contrast, a nanotextured surface left nowhere for the salt to adhere. On these surfaces, evaporating salt water built jellyfish-like salt critters that rose from the surface and, eventually, broke off and rolled away, leaving the surface pristine. (Image credit: S. McBride; research credit: S. McBride et al.; via Physics Today)
https://fyfluiddynamics.com/2024/10/self-cleaning-with-salt-critters/
#droplets #evaporation #fluidDynamics #physics #science #selfCleaning #superhydrophobic
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Even freshwater contains trace salts and minerals that cause scaly buildups as they evaporate. Getting rid of the scale usually requires toxic chemicals and/or lots of scrubbing, neither of which are desirable at the industrial level. At the same time, we’re extremely limited in the amount of freshwater that we have available; only about 1% of Earth’s water is liquid and fresh. If we could use salt water in more industrial processes, that would preserve freshwater for drinking and agriculture. But how do we tackle the scaly buildup?
(A) On microtextured surfaces, salt from evaporating drops can work its way into the gaps, destroying the superhydrophobicity of the surface. (B) In contrast, nanotextured surfaces give the salt nowhere to adhere, resulting in “salt critters” that grow upward and detach.Enter “salt critters.” Researchers found that when salt water evaporated from microtextured surfaces designed to shed water, salt would eventually build up in the gaps, breaking the hydrophobic effect and allowing scale to build up. In contrast, a nanotextured surface left nowhere for the salt to adhere. On these surfaces, evaporating salt water built jellyfish-like salt critters that rose from the surface and, eventually, broke off and rolled away, leaving the surface pristine. (Image credit: S. McBride; research credit: S. McBride et al.; via Physics Today)
https://fyfluiddynamics.com/2024/10/self-cleaning-with-salt-critters/
#droplets #evaporation #fluidDynamics #physics #science #selfCleaning #superhydrophobic
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The intense heat from wildfires fuels updrafts, lifting smoke and vapor into the atmosphere. As the plume rises, water vapor cools and condenses around particles (including ash particles) to form cloud droplets. Eventually, that creates the billowing clouds we see atop the smoke. These pyrocumulus clouds, like this one over California’s Line fire in early September 2024, can develop further into full thunderstorms, known in this case as pyrocumulonimbus. The storm from this cloud included rain, strong winds, lightning, and hail. Unfortunately, storms like these can generate thousands of lightning strikes, feeding into the wildfire rather than countering it. (Image credit: L. Dauphin; via NASA Earth Observatory)
https://fyfluiddynamics.com/2024/10/when-fires-make-rain/
#cloudFormation #convection #fluidDynamics #physics #pyrocumulonimbus #pyrocumulus #science #thunderstorm #turbulence #updrafts #wildfire
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The intense heat from wildfires fuels updrafts, lifting smoke and vapor into the atmosphere. As the plume rises, water vapor cools and condenses around particles (including ash particles) to form cloud droplets. Eventually, that creates the billowing clouds we see atop the smoke. These pyrocumulus clouds, like this one over California’s Line fire in early September 2024, can develop further into full thunderstorms, known in this case as pyrocumulonimbus. The storm from this cloud included rain, strong winds, lightning, and hail. Unfortunately, storms like these can generate thousands of lightning strikes, feeding into the wildfire rather than countering it. (Image credit: L. Dauphin; via NASA Earth Observatory)
https://fyfluiddynamics.com/2024/10/when-fires-make-rain/
#cloudFormation #convection #fluidDynamics #physics #pyrocumulonimbus #pyrocumulus #science #thunderstorm #turbulence #updrafts #wildfire
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In his latest “cutaway” video, Steve Mould takes a look at how you can nest siphons to create a system that periodically flushes itself. This kind of water-powered timer is useful in, say, public restrooms with a urinal system that collectively flushes every once in a while. In the video, Mould talks through each step of the system and some of the challenges he ran into when trying to create a pseudo-2D version of it. As is often the case with these videos, it’s a strangely satisfying process to watch. (Video and image credit: S. Mould)
https://fyfluiddynamics.com/2024/09/breaking-down-a-water-powered-timer/
#engineering #flowVisualization #fluidDynamics #physics #science #siphon #urinalDynamics
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In his latest “cutaway” video, Steve Mould takes a look at how you can nest siphons to create a system that periodically flushes itself. This kind of water-powered timer is useful in, say, public restrooms with a urinal system that collectively flushes every once in a while. In the video, Mould talks through each step of the system and some of the challenges he ran into when trying to create a pseudo-2D version of it. As is often the case with these videos, it’s a strangely satisfying process to watch. (Video and image credit: S. Mould)
https://fyfluiddynamics.com/2024/09/breaking-down-a-water-powered-timer/
#engineering #flowVisualization #fluidDynamics #physics #science #siphon #urinalDynamics
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Mischt man anishaltige Spirituosen mit Wasser, werden sie trüb. Ein mathematisches Modell kann die dafür verantwortlichen mikroskopischen Vorgänge nun endlich erklären.#Lebensmittelchemie #Physik #Fluiddynamik #Ouzo-effekt #Lebensmittel #Alkohol #Mathematik
Mathematiker entschlüsseln den Ouzo-Effekt -
In competition diving, athletes chase a rip entry, the nearly splash-less dive that sounds like paper tearing. Part of a successful rip dive comes in the impact, where divers try to open a small air cavity with their hands that their entire body then enters. But the other key component happens below the surface, where divers bend at the hips once underwater. This maneuver enlarges the air cavity underwater and disrupts the formation of a jet that would typically shoot back upwards. Done properly, the result is an entry with little to no splash at the surface and a panel full of pleased judges. (Image credits: top – A. Pretty/Getty Images, other – E. Gregorio; research credit: E. Gregorio et al.; via Science News; submitted by Kam-Yung Soh)
Sequence of images showing a synthetic diver bending underwater to disrupt splash formation.Related topics: Rip entry physics, how pelicans dive safely, and how boobies plunge dive
This post marks the end of our Olympic coverage for this year’s Games, but if you missed any previous entries, you can find them all here.
https://fyfluiddynamics.com/2024/08/paris-2024-diving/
#cavity #diving #fluidDynamics #jets #olympics #Paris2024 #physics #science #sports #waterEntry
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Inject a less viscous fluid into a gap filled with a more viscous fluid, and you’ll get finger-like patterns spreading radially. Here, researchers put a twist on this viscous fingering by taking turns injecting different liquids. Each injection cycle disrupts what came before, layering fingering patterns on fingering patterns. The results resemble fireworks. Happy 4th of July! (Image credit: C. Chou et al.)
https://fyfluiddynamics.com/2024/07/viscous-fireworks/
#2023gofm #flowVisualization #fluidDynamics #fluidsAsArt #instability #physics #SaffmanTaylorInstability #science #viscousFingering
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Inject a less viscous fluid into a gap filled with a more viscous fluid, and you’ll get finger-like patterns spreading radially. Here, researchers put a twist on this viscous fingering by taking turns injecting different liquids. Each injection cycle disrupts what came before, layering fingering patterns on fingering patterns. The results resemble fireworks. Happy 4th of July! (Image credit: C. Chou et al.)
https://fyfluiddynamics.com/2024/07/viscous-fireworks/
#2023gofm #flowVisualization #fluidDynamics #fluidsAsArt #instability #physics #SaffmanTaylorInstability #science #viscousFingering
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That's a weird cloud formation. Is it a small shelf cloud or a rolling vortex? Contrast added as a side effect of HDR. It's rolling overhead to the west and is widening but diffusing rapidly and the ends branch out. #CloudStodon #Clouds #FluidDynamics
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An ultrasoft viscoelastic fluid drips in this research poster from the Gallery of Soft Matter. Complex materials like this one have stretchy, elastic behaviors typical of a solid along with the flowing, viscous properties of a fluid. Here, gravity overcomes the material’s elasticity, leaving it to sag and flow. As that happens, the fluid must slide past air, and the density difference between the two fluids creates the small distortions seen on the liquid sheet. This is an example of a Rayleigh-Taylor instability. (Image credit: J. Hwang et al.)
https://fyfluiddynamics.com/2024/06/dripping-viscoelastics/
#2024gosmp #flowVisualization #fluidDynamics #instability #physics #RayleighTaylorInstability #science #viscoelasticity
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An ultrasoft viscoelastic fluid drips in this research poster from the Gallery of Soft Matter. Complex materials like this one have stretchy, elastic behaviors typical of a solid along with the flowing, viscous properties of a fluid. Here, gravity overcomes the material’s elasticity, leaving it to sag and flow. As that happens, the fluid must slide past air, and the density difference between the two fluids creates the small distortions seen on the liquid sheet. This is an example of a Rayleigh-Taylor instability. (Image credit: J. Hwang et al.)
https://fyfluiddynamics.com/2024/06/dripping-viscoelastics/
#2024gosmp #flowVisualization #fluidDynamics #instability #physics #RayleighTaylorInstability #science #viscoelasticity
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Massive black holes drag and warp the spacetime around them in extreme ways. Observing these effects firsthand is practically impossible, so physicists look for laboratory-sized analogs that behave similarly. Fluids offer one such avenue, since fluid dynamics mimics gravity if the fluid viscosity is low enough. To chase that near-zero viscosity, experimentalists turned to superfluid helium, a version of liquid helium near absolute zero that flows with virtually no viscosity. At these temperatures, vorticity in the helium shows up as quantized vortices. Normally, these tiny individual vortices repel one another, but a spinning propeller — much like the blades of a blender — draws tens of thousands of these vortices together into a giant quantum vortex.
Here superfluid helium whirls in a quantum vortex.With that much concentrated vorticity, the team saw interactions between waves and the vortex surface that directly mirrored those seen in black holes. In particular, they detail bound states and black-hole-like ringdown phenomena. Now that the apparatus is up and running, they hope to delve deeper into the mechanics of their faux-black holes. (Image credit: L. Solidoro; research credit: P. Švančara et al.; via Physics World)
https://fyfluiddynamics.com/2024/05/black-holes-in-a-blender/
#astrophysics #blackHole #fluidDynamics #physics #quantumVortex #science #superfluid #superfluidHelium #vortices #vorticity
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Massive black holes drag and warp the spacetime around them in extreme ways. Observing these effects firsthand is practically impossible, so physicists look for laboratory-sized analogs that behave similarly. Fluids offer one such avenue, since fluid dynamics mimics gravity if the fluid viscosity is low enough. To chase that near-zero viscosity, experimentalists turned to superfluid helium, a version of liquid helium near absolute zero that flows with virtually no viscosity. At these temperatures, vorticity in the helium shows up as quantized vortices. Normally, these tiny individual vortices repel one another, but a spinning propeller — much like the blades of a blender — draws tens of thousands of these vortices together into a giant quantum vortex.
Here superfluid helium whirls in a quantum vortex.With that much concentrated vorticity, the team saw interactions between waves and the vortex surface that directly mirrored those seen in black holes. In particular, they detail bound states and black-hole-like ringdown phenomena. Now that the apparatus is up and running, they hope to delve deeper into the mechanics of their faux-black holes. (Image credit: L. Solidoro; research credit: P. Švančara et al.; via Physics World)
https://fyfluiddynamics.com/2024/05/black-holes-in-a-blender/
#astrophysics #blackHole #fluidDynamics #physics #quantumVortex #science #superfluid #superfluidHelium #vortices #vorticity
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Massive black holes drag and warp the spacetime around them in extreme ways. Observing these effects firsthand is practically impossible, so physicists look for laboratory-sized analogs that behave similarly. Fluids offer one such avenue, since fluid dynamics mimics gravity if the fluid viscosity is low enough. To chase that near-zero viscosity, experimentalists turned to superfluid helium, a version of liquid helium near absolute zero that flows with virtually no viscosity. At these temperatures, vorticity in the helium shows up as quantized vortices. Normally, these tiny individual vortices repel one another, but a spinning propeller — much like the blades of a blender — draws tens of thousands of these vortices together into a giant quantum vortex.
Here superfluid helium whirls in a quantum vortex.With that much concentrated vorticity, the team saw interactions between waves and the vortex surface that directly mirrored those seen in black holes. In particular, they detail bound states and black-hole-like ringdown phenomena. Now that the apparatus is up and running, they hope to delve deeper into the mechanics of their faux-black holes. (Image credit: L. Solidoro; research credit: P. Švančara et al.; via Physics World)
https://fyfluiddynamics.com/2024/05/black-holes-in-a-blender/
#astrophysics #blackHole #fluidDynamics #physics #quantumVortex #science #superfluid #superfluidHelium #vortices #vorticity
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Massive black holes drag and warp the spacetime around them in extreme ways. Observing these effects firsthand is practically impossible, so physicists look for laboratory-sized analogs that behave similarly. Fluids offer one such avenue, since fluid dynamics mimics gravity if the fluid viscosity is low enough. To chase that near-zero viscosity, experimentalists turned to superfluid helium, a version of liquid helium near absolute zero that flows with virtually no viscosity. At these temperatures, vorticity in the helium shows up as quantized vortices. Normally, these tiny individual vortices repel one another, but a spinning propeller — much like the blades of a blender — draws tens of thousands of these vortices together into a giant quantum vortex.
Here superfluid helium whirls in a quantum vortex.With that much concentrated vorticity, the team saw interactions between waves and the vortex surface that directly mirrored those seen in black holes. In particular, they detail bound states and black-hole-like ringdown phenomena. Now that the apparatus is up and running, they hope to delve deeper into the mechanics of their faux-black holes. (Image credit: L. Solidoro; research credit: P. Švančara et al.; via Physics World)
https://fyfluiddynamics.com/2024/05/black-holes-in-a-blender/
#astrophysics #blackHole #fluidDynamics #physics #quantumVortex #science #superfluid #superfluidHelium #vortices #vorticity
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Some 20,000 years ago, a massive star blew off a ring of dust and gas that expanded into the surrounding interstellar medium. Later, in 1987, the star exploded as supernova 1987A. That explosion lit the surrounding area, revealing a clumpy ring astronomers have struggled to explain. But a new team believes they have a fluid dynamical answer: the Crow instability.
Closer to home, we see the Crow instability when an airplane’s contrails break up. It happens when two vortices that rotate in opposite directions are close to one another. Any wobble in one vortex is enhanced by the influence of its neighbor. Eventually, this breaks the original vortices apart and causes them to reform as a series of smaller vortex rings.
A comparison between an image of SN 1987A and an illustration of the vortex ring interaction thought to create that shape.In the case of supernova 1987A, the researchers propose that the star originally blew off two vortex rings that, due to their mutual influence, broke down into a clumpy ring of vortices. (Image credits: NASA/ESA/CSA/M. Matsuura/R. Arendt/C. Fransson and NASA/ESA/A. Angelich + M. Wadas et al.; research credit: M. Wadas et al.; via APS Physics)
https://fyfluiddynamics.com/2024/05/supernova-rings/
#astrophysics #CrowInstability #fluidDynamics #instability #physics #science #supernova #vortexRings #vortices