Here’s a neat bit of fluid dynamics derived from a day at the beach! Our experiment begins with well-mixed (and likely compacted) sand grains and sea water in a bottle. Keep reading
Tag: granular flow
The Strangeness of Sand
Sand and other granular materials can flow, jam, and transmit forces in counterintuitive ways. This Lutetium Project video gives a nice overview of some of these bizarre properties. Many of 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
Shear in Shaken Sands
The dynamics inside a shaken granular material, like sand, are fascinatingly complex. In this study, researchers used x-ray radiograms to peer inside a horizontally-shaken container of sand. They found that Keep reading
Unifying Sediment Transport Theory
On windy days, streaks of snowflakes snake in the air above a mountaintop snowfield. And when snorkeling in the surf, you can watch the inbound waves sculpt underwater ripples in Keep reading
Dunes Avoid Collisions
The speed at which a dune migrates depends on its size; smaller dunes move faster than larger ones. That speed differential implies that small dunes should frequently collide into and Keep reading
The Sand Sea’s End
The northern extent of Africa’s Namib Sand Sea ends where the reddish dunes meet the Kuiseb River and the hard, rocky land on its other side. Within the sand sea, Keep reading
Martian Landslides
Sometimes there are advantages to studying planetary physics beyond Earth. Mars does not have plate tectonics, vegetation, or the level of erosion we do, allowing geological features like those left Keep reading
Giving Chocolate that Smooth Finish
Anyone who’s tried to make chocolate confections at home can tell you that achieving that perfect smooth consistency isn’t easy. It was only after Rodolphe Lindt invented the process of Keep reading
Granular Instabilities
Granular mixtures show surprising similarities to fluids, even though their underlying physics differ. The latest example of this is a Rayleigh-Taylor-like instability that occurs when heavy particles sit atop lighter Keep reading