The most dangerous and destructive part of a tropical cyclone isn’t the wind or rain; it’s the storm surge of water moving inland. This landward shift of ocean takes place Keep reading
Tag: shear
Sunset Swirls
This gorgeous photograph of Kelvin-Helmholtz clouds was taken in late December in Slovenia by Gregor Riačevič. The wave-like shape of the Kelvin-Helmholtz instability comes from shear between two fluid layers Keep reading
Shear and Convection in Turbulence
In nature, we often find turbulence mixed with convection, meaning that part of the flow is driven by temperature variation. Think thunderstorms, wildfires, or even the hot, desiccating winds of Keep reading
Colorful Kelvin-Helmholtz Clouds
Like breaking waves at the beach, these wavy clouds curl but only for a moment. The photo was captured near sunset on a late August evening in Arlington, MA. This Keep reading
When Shear Meets Slip
One of the classic concepts students learn early in their fluids education is the no-slip condition. In essence, this idea says that friction between a solid object — say, a Keep reading
The Vortex Beneath a Drop
While we’re most used to seeing levitating Leidenfrost droplets on a solid surface, such drops can also form above a liquid bath. In fact, the smoothness of the bath’s surface, Keep reading
Bioluminescence at the Beach
A bioluminescent phytoplankton bloom is causing a stir among California beachgoers. During the daytime, aggregations of Lingulodinium polyedra appear reddish-brown in color (think the classic ‘red tide’). But at night Keep reading
Sliding Foams
What happens when a foam interacts with a sliding surface? That’s the question at the heart of this study, which finds three major regimes of foam-surface interaction. On smooth surfaces Keep reading
Wave Clouds in the Front Range
Last Sunday night metro Denver was treated to a rare sight: clouds resembling breaking waves formed near sunset. These are Kelvin-Helmholtz clouds, and the comparison to ocean waves is apt, Keep reading
Shearing Grains
Granular materials, like beads and sand, demonstrate both solid and fluid-like behaviors, which makes them difficult to study. Traditionally, one method for studying how fluids respond to deformation places the Keep reading