#granular material

[fuckyeahfluiddynamics]

Why Unpaved Roads Washboard

As anyone who has regularly traveled unpaved roads knows, they have a tendency to develop regularly spaced corrugations, otherwise known as washboarding.  (Video and image credit: Practical Engineering; research credit: N. Taberlet et al. and I. Hewitt et al.)

[fuckyeahfluiddynamics]

Seeing Stress in an Avalanche

Researchers sometimes study avalanches and other granular flows in a rolling drum, where grains can cascade down continuously. Here, the twist is that they've done it with photoelastic disks, which show stress patterns when viewed under crossed polarizing filters. (Video and image credit: R. Hodgson et al.)

[fuckyeahfluiddynamics]

"Cracked Earth"

Branching cracks wend through the slopes of Utah in this photograph by Matt Payne. It may seem strange to feature something so dry on a blog about fluid dynamics, but everything seen here depends as much on air and water as on soil, rock, and sand.  (Image credit: M. Payne; via ILPOTY)

[fuckyeahfluiddynamics]

Flow Through Granular Beds

We often rely on water draining through beds of grains, whether it's the soil foundation beneath a building or the sand-and-gravel-filter used in water treatment. But how does water move through these tortuous porous passages? (Video and image credit: J. Choi et al.)

[fuckyeahfluiddynamics]

Particles Separate When Flowing Downhill

When particle-laden fluids like a mudslide flow downhill, even well-mixed particles can wind up separating. To explore how this works, researchers put glass spheres--of two different sizes but equal density--into silicone oil and let it flow down an incline. (Video and image credit: Y. Ba et al.)

[fuckyeahfluiddynamics]

Waves Over Sand Ripples

Look beneath the waves on a beach or in a bay, and you'll find ripples in the sand. Passing waves shape these sandforms and can even build them to heights that require dredging to keep waterways passable to large ships. (Image credit: D. Hall; research credit: S. DeVoe et al.; via Eos)

[fuckyeahfluiddynamics]

Instabilities in a Particle Flow

Even though particles are not (strictly speaking) a fluid, they often behave like one. Here, researchers investigate what happens when two layers of particles--with different size and density--slide down an incline together.  (Video and image credit: M. Ibrahim et al.; via GFM)

[fuckyeahfluiddynamics]

On the Mechanics of Wet Sand

Sand is a critical component of many built environments. As most of us learn (via sand castle), adding just the right amount of water allows sand to be quite strong. But with too little water -- or too much -- sand is prone to collapse. (Video and image credit: Practical Engineering) Read the full article