vorticity

Questo set è uno dei più importanti che ho fatto , non per la destinazione che ha avuto , o per il suo successo mediatico , ma per quello che ha scatenato dentro di me . Scattare con @lucadenardo è stato come già dissi un vortice di emozioni . Ho appreso , mi sono emozionata ascoltando e ballando (dire che stavo posando sarebbe come bestemmiare) , mi sono divertita , ho sofferto scontrandomi con dei blocchi che mi portavo dietro dal l'adolescenza .
Da questo set sono cambiata e non quei cambiamenti che vedi dal giorno alla notte che quasi ti rendono una persona completamente diversa . Ho messo dei puntini sulle i , ho scavalcato paure , afferrato le redini del mio io … Anzi no , che dico??
finalmente da lì ho imparato ad allentare la presa , ho capito che abbassare dei muri e spalancare le porte a certe emozioni , diventate vulnerabili in realtà ti permette di provare tutto più forte . Grazie Luca per avermi inviato questo scatto oggi così , senza che me lo aspettassi . Grazie perché posso affermare con certezza che ho ancora strada da fare per liberare completamente il mio essere da catene invisibili , ma tu con parole e foto mi hai dato le istruzioni per usare quel mazzo enorme di chiavi che già avevo a disposizione .
Grazie

"Levare Levis"
External image

“Levare Levis”

Gravity Shift, Ink Dewdrop Dives Towards Sky

Solar Wind, Lunar Tide, Noise Frozen In Time

Time-Lapse, Synapse Inside Depths Of Mind

Sublime Thoughts Collide, Spread Worldwide

Mixed media on canvas 100x30x2cm (39.3x11.8x0.7in)

Available for sale, please contact Ingress Vortices

Seven waterspouts align as lava from the Hawaiian volcano Kilauea pours into the ocean in this striking photo from photographer Bruce Omori. Like many waterspouts–and their landbound cousins dust devils–these vortices are driven by variations in temperature and moisture content. Near the ocean surface, air and water vapor heated by the lava create a warm, moist layer beneath cooler, dry air. As the warm air rises, other air is drawn in by the low pressure left behind. Any residual vorticity in the incoming air gets magnified by conservation of angular momentum, like a spinning ice skater pulling her arms in. This creates the vortices, which are made visible by entrained steam and/or moisture condensing from the rising air. (Photo credit: B. Omori, via HPOTD; submitted by jshoer)

“Not all who wander are lost…some are just storm chasing.”

Today the Department of Awesome Natural Phenomena is marveling at this extraordinary time-lapse video created by storm chaser and wedding photographer Mike Olbinski. After 18 days worth of storm chasing (20,000 miles of driving through 9 states and 7 tornadoes), Olbinski edited his footage down to 60,000 time-lapse frames to create this jaw-dropping 6-minute-video entitled Vorticity:

[via Sploid]

2

The Beerenberg effect

These strange clouds you see whirling around Jan Mayen’s Beerenberg are known as ‘Von Karman vortices’. These long chains of spiral clouds can form nearly any place where fluid flow is disturbed by an object. In this case a 2277m high stratovolcano in the middle of the Greenland Sea. Von Karman vortices often occur around the tall peaks of volcanic islands. As wind encounters a peak the flow is disturbed, this disturbance in turn forms a double row of vortices (a whirling mass such as a whirlwind), which takes an alternate direction of rotation.

Keep reading

Reader unquietcode asks:

I saw this post recently and it made me wonder what’s going on. If you look in the upper right of the frame as the camera submerges, you can see a little vortex of water whirring about. Even with the awesome power of the wave rolling forward a little tornado of water seems able to stably form. Any idea what causes this phenomenon?

This awesome clip was taken from John John Florence’s “& Again” surf video. What you’re seeing is the vortex motion of a plunging breaking wave. As ocean waves approach the shore, the water depth decreases, which amplifies the wave’s height. When the wave reaches a critical height, it breaks and begins to lose its energy to turbulence. There are multiple kinds of breaking waves, but plungers are the classic surfer’s wave. These waves become steep enough that the top of the wave  overturns and plunges into the water ahead of the wave. This generates the vortex-like tube you see in the animation. Such waves can produce complicated three-dimensional vortex structures like those seen in this video by Clark Little. Any initial variation in the main vortex gets stretched as the wave rolls on, and this spins up and strengthens the rib vortices seen wrapped around the primary vortex. (Source video: B. Kueny and J. Florence)

This awesome image from NASA reveals what Jupiter looks like when viewed from its south pole. And it looks like the biggest spin art ever.

This incredible sight is a polar stereographic projection captured by the Cassini spacecraft on December 11th and 12th during its Jupiter flyby en route to Saturn.

NASA describes some of Jupiter’s features in this image:

“The map shows a variety of colorful cloud features, including parallel reddish-brown and white bands, the Great Red Spot, multi-lobed chaotic regions, white ovals and many small vortices. Many clouds appear in streaks and waves due to continual stretching and folding by Jupiter’s winds and turbulence. The bluish-gray features along the north edge of the central bright band are equatorial “hot spots,” meteorological systems such as the one entered by NASA’s Galileo probe. Small bright spots within the orange band north of the equator are lightning-bearing thunderstorms. The polar region shown here is less clearly visible because Cassini viewed it at an angle and through thicker atmospheric haze.”

[via Twisted Sifter]

8

New FYFD video! Learn all about salps, vortex rings, and underwater robots. Thanasi Athanassiadis takes me inside his lab and his newly published research into how proximity affects the thrust two vortex rings can produce. 

There are a ton of little things I love about how this video came out, especially the chalkboard animations. Check it the full video below and click through to the video description for lots more information about salps and vortex rings.

(Image and video credits: N. Sharp and A. Athanassiadis; Original salp images: A. Migotto and D. Altherr)

Von Karman vortices

Both the ocean and atmosphere are fluids, in constant motion. On our limited “human”-scale, we are aware of this motion when we feel the wind blow,  or when we encounter a current running along the beach while swimming. Yet our eyes alone can rarely observe the larger scale of fluid motion in the  ocean and atmosphere.

Technical description: “As a fluid particle flows toward the leading edge of a  cylinder, the pressure on the particle rises from the free stream pressure  to the stagnation pressure. The high fluid pressure near the leading edge   impels flow about the cylinder as boundary layers develop about both sides. The high pressure is not sufficient to force the flow about the back of the  cylinder at high Reynolds numbers. Near the widest section of the cylinder,  the boundary layers separate from each side of the cylinder surface and form  two shear layers that trail aft in the flow and bound the wake. Since the  innermost portion of the shear layers, which is in contact with the cylinder,  moves much more slowly than the outermost portion of the shear layers, which  is in contact with the free flow, the shear layers roll into the near wake,  where they fold on each other and coalesce into discrete swirling vortices.  A regular pattern of vortices, called a vortex street, trails aft in the wake.”

(Source)

everyonelikespotatissallad asks:

so, how is lift actually generated? i’ve been going through Anderson’s Introduction to Flight (6th Ed.) and while it offers the derivation of various equations very thoroughly, it barely touches on why lift is generated, or how camber contributes to the increase of C(L) 

This is a really good question to ask. There are a lot of different explanations for lift out there (and some of the common ones are incorrect). The main thing to know is that a difference in pressure across the wing–low pressure over the top and higher pressure below–creates the net upward force we call lift. It’s when you ask why there’s a pressure difference across the wing that explanations tend to start diverging. To be clear, aerodynamicists don’t disagree about what produces lift - we just tend to argue about which physical explanation (as opposed to just doing the math) makes the most sense. So here are a couple of options:

Newton’s 3rd Law

Newton’s third law states that for every action there is an equal and opposite reaction. If you look at flow over an airfoil, air approaching the airfoil is angled upward, and the air leaving the aifoil is angled downward. In order to change the direction of the air’s flow, the airfoil must have exerted a downward force on the air. By Newton’s third law, this means the air also exerted an upward force–lift–on the airfoil. 

The downward force a wing exerts on the air becomes especially obvious when you actually watch the air after a plane passes:

Circulation

This one can be harder to understand. Circulation is a quantity related to vorticity, and it has to do with how the direction of velocity changes around a closed curve. Circulation creates lift (which I discuss in some more detail here.) How does an airfoil create circulation, though? When an airfoil starts at rest, there is no vorticity and no circulation. As you see in the video above, as soon as the airfoil moves, it generates a starting vortex. In order for the total circulation to remain zero, this means that the airfoil must carry with it a second, oppositely rotating vortex. For an airfoil moving right to left, that carried vortex will spin clockwise, imparting a larger velocity to air flowing over the top of the wing and slowing down the air that moves under the wing. From Bernoulli’s principle, we know that faster moving air has a lower pressure, so this explains why the air pressure is lower over the top of the wing.

Asymmetric Flow and Bernoulli’s Principle

There are two basic types of airfoils - symmetric ones (like the one in the first picture above) and asymmetric, or cambered, airfoils (like the one in the image immediately above this). Symmetric airfoils only generate lift when at an angle of attack. Otherwise, the flow around them is symmetric and there’s no pressure difference and no lift. Cambered airfoils, by virtue of their asymmetry, can generate lift at zero angle of attack. Their variations in curvature cause air flowing around them to experience different forces, which in turn causes differing pressures along the top and the bottom of the airfoil surface. A fluid particle that travels over the upper surface encounters a large radius of curvature, which strongly accelerates the fluid and creates fast, low-pressure flow. Air moving across the bottom surface experiences a lesser curvature, does not accelerate as much, and, therefore, remains slower and at a higher pressure compared to the upper surface.

(Image credit: M. Belisle/Wikimedia; National Geographic/BBC2; O. Cleynen/Wikimedia; video credit: J. Capecelatro et al.)

vimeo

Vorticity, A Stunning Time Lapse That Captures the Incredible Beauty of Springtime Tornadoes

vimeo

Sometimes it takes timelapse photography to truly appreciate the dynamic behavior of our atmosphere. In “The Chase” Mike Olbinski, whose work we’ve featured previously, has captured some of the most incredible and stunning weather timelapse footage I have ever seen. Despite watching it repeatedly, I continue to be awed to the point that I have no words. Seriously, just watch it. Be amazed by the drama of our sky. (Video credit: M. Olbinski)