Justdroppedin
02-18-2021, 12:39 PM
Windy + harmonic oscillation......
Most commonly know as Von Karman instability.
Fun fact : to prevent these you can apply a spiral pattern on the outside of the cylinder, often used for industrial chimneys, or car radio antennas to cite a few.
This is precisely why truck drivers put a 1/2 twist in the straps holding down their load that will be exposed to the wind. The twist keeps the straps from oscillating relentlessly while driving at highway speeds. If allowed to oscillate they fatigue and fray much more quickly -- not to mention the terribly annoying noise of the strap flapping.
https://thumbs.gfycat.com/PortlyCapitalAfricanwilddog-size_restricted.gif
Most commonly know as Von Karman instability.
Fun fact : to prevent these you can apply a spiral pattern on the outside of the cylinder, often used for industrial chimneys, or car radio antennas to cite a few.
This is precisely why truck drivers put a 1/2 twist in the straps holding down their load that will be exposed to the wind. The twist keeps the straps from oscillating relentlessly while driving at highway speeds. If allowed to oscillate they fatigue and fray much more quickly -- not to mention the terribly annoying noise of the strap flapping.
https://thumbs.gfycat.com/PortlyCapitalAfricanwilddog-size_restricted.gif