A fixed cylinder will shed alternating vortices in its wake, but one allowed to oscillate forward and backward in the flow instead sheds simultaneous vortices. The shape of the wake Keep reading
Tag: oscillation
Leidenfrost Stars
Atop a very hot surface, liquids can instantly vaporize, leaving a drop levitating on a layer of its own vapor. These Leidenfrost droplets demonstrate all kinds of interesting behaviors, including self-propulsion, explosion, and star-shaped Keep reading
Settling in Straws
At some point in your life, you’ve probably stuck your finger over the end of a straw and used it to pick up the liquid you’re drinking. If you lift Keep reading
Shaping and Levitating Droplets
Opposing ultrasonic speakers can be used to trap and levitate droplets against gravity using acoustic pressure. Changes to field strength can do things like bring separate objects together or flatten droplets. Keep reading
Pendulum Soap Flow Viz
Soap films are a handy way to create nearly two-dimensional flow fields. Previously we’ve seen them used to show wake structures of pitching foils, flapping flags, and multiple bodies. In Keep reading
Droplet Springs
Prior to reaching terminal velocity, a falling droplet typically oscillates between a prolate shape (like an American football about to be kicked) and an oblate one (like that same football Keep reading
Leidenfrost Dynamics
When a liquid impacts a solid heated well above the liquid’s boiling point, droplets can form, levitating on a thin film of vapor that helps insulate them from the heat Keep reading
Space Didgeridoo
This week astronaut Don Pettit is playing with acoustic oscillators on the space station. He and Dan Burbank transform some of their vacuum cleaner tubes into didgeridoo-like instruments. By buzzing Keep reading
Why Walking with Coffee is Tough
Almost everyone is familiar with the problem of coffee or tea sloshing over the sides of a mug as one walks, but this may be the first time researchers have Keep reading
Sloshing Dynamics
[original media no longer available] Sloshing refers to the motion of a liquid inside a moving container, for example, in tanker trucks or inside a spacecraft’s fuel tank. The motion Keep reading