#rheoscopic fluid

[fuckyeahfluiddynamics]

Peering Into the Gap

This video offers a glimpse into turbulence developing in a classic flow set-up, a Taylor-Couette cylinder. The apparatus consists of two upright, concentric cylinders; the outer cylinder is fixed, and the inner one rotates. (Video credit: D. van Gils)

[everythingispermited]

I made another Rheoscopic bottle. Got some different colors coming. Hope you guys like them. Feel free to DM me for prices, any color is available.

Disclaimer: Not for drinking!!!

[fuckyeahfluiddynamics]

Since we spend so much of our lives around transparent fluids like air and water, we often miss seeing some of their coolest-looking flows. Here, we see a layer of water only 3 centimeters deep but a full meter wide. It’s seeded with tiny crystals that reflect light depending on their orientation, which allows us to see the flow. Initially, the tank is spun up, then left stationary for 2 hours while evaporation cools the water. 

Normally, the resulting flow would be too slow to notice, but that’s where the magic of timelapse comes in. With it, we can see the wriggling dark lines marking areas where cool, dense water sinks and brighter regions where warm fluid rises. What begins as an array of polygonal convection cells quickly merges into a couple of large, rounded cells. Check out the full video below, where you can see the streaming patterns far better than in animation. (Image and video credit: UCLA Spinlab)

[everythingispermited]

These are "Rheoscopic fluid" bottles. It doesn't do anything but look cool when you shake them up. I'm selling these and any other I make. DM me if you'd like one, I can make them in any bottle you'd like. I'm going to try and start an Etsy for both these and my paracord stuff. I'll post the link when I get that going.

[fuckyeahfluiddynamics]

Are you staring into the eye of a hurricane or watching the spin of a simple desk toy? Part of the beauty of fluid dynamics is recognizing how similar they both are. This is high-speed footage of a toy known as a “Vortex Dome,” which contains a fluid filled with tiny mica particles that react to local forces and allow users to “see” the flow. Before the video begins, the toy has been spinning for long enough that the fluid inside rotates as if it were a solid body. Then an unseen hand sets the disk spinning in the opposite direction and we observe what happens.

Fluid at the outer edge of the toy has to immediately change direction due to friction with the wall. That change in momentum slowly passes from the wall inward as viscosity between one layer of fluid to the next passes that signal. This creates the rolls we see in the first animation. Initially, those rolls are smooth, but they quickly roughen as disturbances in them grow into full-blown turbulence. Meanwhile, viscosity continues to pass the change in rotation inward, ultimately swallowing the entire interior of the toy. Left spinning indefinitely, the disturbances will eventually quiet out and the entire fluid will spin as one. (Image and video credit: D. van Gils)

[fuckyeahfluiddynamics]

One of the great challenges in visualizing fluid flows is the freedom of movement. A fluid particle -- meaning some tiny little bit of fluid we want to follow -- is generally free to move in any direction and even change its shape (but not mass). This makes tracking all of those changes difficult, and it’s part of why there are so many different techniques for flow visualization. The technique an experimenter uses depends on the information they hope to get. 

Often a researcher may want to know about fluid velocity in two or more directions, which can require multiple camera angles and more than one laser sheet illuminating the flow. An alternative to such a set-up is shown above. The injected fluid -- known as a rheoscopic fluid -- contains microscopic reflective particles, in this case mica, that are asymmetric in shape. Imagine a tiny rod, for example. By illuminating the rod from different directions with different colors of light, you can determine the particle’s orientation based on the color it reflects. Since the orientation of the particle depends on the surrounding flow, you can infer how the flow moves. (Image credit and submission: J. C. Straccia; research link: V. Bezuglyy et al.)

[everythingispermited]

[alixero]

~I got crafty~

Dark one is a 'Potion of Undeath' for my Oathbreaker Paladin to use on innocent people because Evil

And the other is just an unassigned Red Potion, so either Health Potion or Potion of Fire Breathing, what ever fits in the moment

My only other two bottles are defective so they will be serving as empty shelf decor lol, though given how much material I still have left I'll likely be making more at some point