|WikiProject Physics / Fluid Dynamics||(Rated Start-class, Mid-importance)|
The Tacoma Narrows link says that Vortex Shedding wasnt' responsible for the bridge collapse, but this page says it is...
Vortex shedding can occur in any fluid, not just air.
Tacoma Narrows Bridge
Tacoma Narrows Bridge collapsed due to Aeroelastic flutter. Vortex shedding is an entirely different phenomenon. Bodies (especially bluff bodies) subjected to high Reynolds Number flow exhibit this phenomenon. Under ideal circumstances, vortex shedding will not take place unless the ideal flow is perturbed a little. (Similar to buckling in an ideal loading on ideal geometry case, it doesn't buckle unless a small perturbation is applied). Someone please verify my statement and make changes.
PS: I vote for merger.
54UV1K 14:21, 8 November 2006 (UTC)
Actually, the Reynolds number doesn't need to be that high, any greater than Re=47 will do. Yes, vortex shedding won't occur in ideal circumstances, but only an infinitesimal disturbance is required, as the non-shedding wake is inherently unstable. Therefore, it is practically unavoidable, and I think it is confusing to include this fact in a page for general consumption. I vote for merger too, the two pages describe the same phenomenon. Any edits I make will be to the vortex street page, it seems a little more in-depth already.
Jmista 07:02, 13 December 2006 (UTC)
Some more info at http://www.helicalstrakes.com/
There's more information about vortex-induced vibration suppression at http://www.helicalstrakes.com, some of which should probably be included here.
I am not associated with the website. I was watching season 1, episode 1 of Impossible Engineering, about the Rio–Antirrio bridge, and they explained how Christopher "Kit" Scruton invented the helical strake (used on the bridge cables). I came to Wikipedia to learn more, but was surprised to find no mention of him at all. A Google search led me to http://www.helicalstrakes.com, that says:
- Christopher Scruton and D. E. J. Walshe, working at the National Physics Laboratory in Great Britain, invented the helical strake and first published the results in 1957 (1).
- 1. C. Scruton and D.E.J. Walshe, A Means for Avoiding Wind-excited Oscillations of Structures with Circular Or Nearly Circular Cross-section, National Physics Laboratory (Great Britain), 1957.
I added the website as a reference to the assertion that optimal pitch for a helical strake to prevent vortex shedding is a 5D pitch. I didn't add the paper as a reference, as I don't have access to it, so can't verify what it says. — Preceding unsigned comment added by 126.96.36.199 (talk) 16:55, 9 July 2016 (UTC)