I suspect demonstrating fluid mechanics was not what this cookbook had in mind when they filmed creamer poured into coffee at 2000 fps, but there’s some awesome droplet breakup, crowning, roiling turbulent mixing, and even some deformed Worthington jets here. It’s a reminder that, even though we may not notice it, fluid dynamics are all around.
Tag: turbulent mixing
Instability in a Jet
This photo shows the development of a flow instability in an axisymmetric jet. On the left, the jet is smooth and fully laminar, but, by the center of the photo, disturbances in the jet have grown large enough to distort the laminar profile. The jet is then in transition; by the right side of the frame, it has reached a turbulent state, as evidenced by the increased mixing (which causes the smoke to disperse more quickly) and intermittency of the flow. #
Saturnian Storm
Back in mid-December, amateur astronomers discovered an enormous new storm on Saturn. The Cassini spacecraft captured this image early in the storm’s history (it now stretches farther around the planet). The fluid dynamics of Saturn’s atmosphere are incredibly complex and well beyond our current understanding, but we can certainly appreciate the majesty of a swirling, turbulent storm half the size of our entire planet. (via APOD, Martian Chronicles)
Turbulent Phytoplankton Eddies
Where warm and cold ocean currents collide, turbulent eddies form and pull up valuable nutrients from the ocean floor. Massive phytoplankton blooms ensue, effectively providing natural flow visualization for the process. #
Wind Turbines and Weather
A new study reports that wind turbine farms may be changing local surface temperatures, resulting in warmer temperatures at night and cooler temperatures during the day. The result is neither surprising nor new; the motion of the propellers increases the turbulence downstream of the turbines. Turbulent flow mixes much better than laminar flow, so air from above the ground is getting mixed into surface air in the wakes. At night, the air next to the ground cools more quickly than air higher up, so the mixing of higher, warmer air results in localized warmer air on the ground. Orange farmers use this effect when they put out fans at night to keep their crops from freezing. #
Turbulent Mixing in the Gulf
Sediments carried by rivers and stirred from the shallows meet the Gulf of Mexico in a vivid display of turbulent mixing. Although turbulence is not well-understood, it is a process vital to our lives. Without turbulence, it would take days for molecular diffusion to mix milk into your coffee! #
