Sandwich a viscous fluid between two transparent plates and then inject a second, less viscous fluid. This is the classic set-up for the Saffman-Taylor instability, a well-studied flow in which Keep reading
Tag: viscous fingering
Fast Fractal Fingers
With the right balance of viscosity and surface tension, many fluid combinations can form fractal or dendritic patterns. Here, researchers use a drop of food coloring atop a mixture of Keep reading
Eruption in a Box
In layers of viscous fluids, lighter and less viscous fluids can displace heavier, more viscous liquids. Here, researchers demonstrate this using four fluids sandwiched between layers of glass and mounted Keep reading
Acrylic Paint Fractals
Here’s a simple fluids experiment you can try at home using acrylic paints, ink, isopropyl alcohol and a few other ingredients. When dropped onto diluted acrylic paint, a mixture of Keep reading
Solid, Liquid, Both?
Materials like oobleck — a suspension of cornstarch particles in water — are tough to classify. In some circumstances, they behave like a fluid, but in others, they act like Keep reading
Granular Fingers
Finger-like shapes often form on fluids injected between glass plates, but what happens when that injected fluid contains particles? That’s the situation in this recent study, where researchers sandwiched a Keep reading
Dendritic
“What happens when two scientists, a composer, a cellist, and a planetarium animator make art?” The answer is “Dendritic,” a musical composition built directly on the tree-like branching patterns found Keep reading
Branching Gels
If you sandwich a viscous fluid between two plates, then pull the plates apart, you’ll often get a complex branching pattern that forms as air pushes its way into the Keep reading
Fingers of Clay
Take a mixture of a viscous liquid – like clay mud – and squeeze it between two glass plates and you’ll create a mostly-round layer of liquid. As you pry Keep reading
Growing Fingers
Branching, tree-like structures are found throughout nature. Take a thin layer of a viscous fluid pressed between two glass plates and inject a less viscous fluid like air and you’ll Keep reading