Talk:Kármán vortex street

Insect related references?

This is so cool. Any references on the insect related reference? Cypa 20:45, 3 September 2005 (UTC)

Sure. I have added a link in the External links section. --Ruleke 08:33, September 7, 2005 (UTC)

(that link was later deleted -- url: http://www.berkeley.edu/news/media/releases/99legacy/6-15-1999.html) 70.137.153.182 11:19, 12 May 2006 (UTC)

Why not, all these sections deal with vortex, the best manner is to create a section about vortex and inside this section include these 2 sections

The range of Re varies with the kinematic viscosity? This either needs to be removed, because it has already been covered by the change in Re, or referenced. If the kinematic viscosity can change the range of Re, the Re is not a suitable scaling parameter, and this seems unlikely.

Jmista 07:22, 13 December 2006 (UTC)

Reference Reynold's number

$\mathrm {Re} ={{\rho {\mathbf {\mathrm {V} } }L} \over {\mu }}={{{\mathbf {\mathrm {V} } }L} \over {\nu }}={{{\mathbf {\mathrm {Q} } }L} \over {\nu }A}$

where:

• ${\mathbf {\mathrm {V} } }$ is the mean fluid velocity (SI units: m/s)
• ${L}$ is a characteristic linear dimension, (traveled length of fluid, or hydraulic diameter when dealing with river systems) (m)
• ${\mu }$ is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/(m·s))
• ${\nu }$ is the kinematic viscosity ($\nu =\mu /$ρ) (m²/s)
• ${\rho }\,$ is the density of the fluid (kg/m³)

--195.137.93.171 (talk) 00:37, 17 December 2010 (UTC)

Merge request

This merge request has been up for a long time now. My intuition is to not merge the two because one is talking about airflow around a compliant object and the other is talking about flows at high Reynold's numbers around non-compliant ones. I will delete the tags in a few days unless I hear an objection. -- Selket ^Talk 04:44, 20 March 2007 (UTC)

I think you should have merged - the topics now have too much content in common, not to mention Aeroelasticity#Flutter. I don't think Vortex shedding relies necessarily on compliance or rigidity of the solid object. Arguably in Aeroelasticity#Flutter, the primary resonance is that of the solid object, not the vortex shedding, which are just weaker, loosely-coupled oscillations, and vice-versa here. Probably vortices will be shed in all cases from one extreme to the other, and all real examples will sit in-between, with more or less contribution from both the solid and the fluid resonances. --195.137.93.171 (talk) 23:55, 16 December 2010 (UTC)

Oh, and we could merge a 3rd topic, as well : Vortex-induced vibration !--195.137.93.171 (talk) 00:15, 17 December 2010 (UTC)

Kármán vortex street not Von Kármán vortex street

Kármán himself called it "Kármán vortex street" in his book Aerodynamics and The Wind and Beyond: "...in London this is called Kármán vortex street, in Berlin Kármánsche Wirbelstrasse...."

Also in textbooks such as Tritton Physical Fluid Dynamics, Oxford University Press--Gisling (talk) 22:35, 23 April 2008 (UTC)

I think the article should probably just be named, and refer to, vortex street (which is a redirect), but I don't know enough about aerodynamics to be sure. splintax ^(talk) 16:26, 11 December 2016 (UTC)

Bluff body

The article is somewhat opaque to the layman and at the very least the lead should be written in plain English see wp:what wikipedia is not under "not a textbook". Could someone at least explain in the lead what a bluff body is? The best I can find is this. The explanation here says "(aerospace engineering) A body having a broad, flattened front, as in some reentry vehicles" but I don't think that necessarily applies here as this reference shows various shapes including a sphere. Richerman (talk) 23:23, 14 December 2008 (UTC)

OK I've changed a few things and added some explanations to try to make the article a bit more accessible, but as I know next to nothing about fluid dynamics, someone will need to check to make sure it still makes sense. The other thing is - I can see the similarities between a singing telephone wire and Galloping Gertie, so, is aeroelastic flutter caused by a vortex street? If so, there should be links between this article and aeroelasticity. Richerman (talk) 00:44, 15 December 2008 (UTC)

Source code

Is there source code deposited anywhere for the Cesareo de La Rosa Siqueira animation that we could reference? The author might consider deposting code directly into the figure's legend on Commons. Navuoy (talk) 13:08, 8 February 2009 (UTC)

Have I correctly defined d in the Analysis section?

I'm not qualified to edit the Analysis section, but the previous version was so unsatisfactory that I've attempted to do so anyway by applying some common sense. In particular, I've assumed that the “cylinder” referred to in the definition of $d$ is the same as the “bluff body” referred to in the earlier section, and that $d$ is a measure of the diameter (suitably adjusted) of that body. I'd be delighted if someone could review what I've done and correct or improve it as necessary.

W.F.Galway (talk) 01:45, 19 February 2010 (UTC)

Hmm, since the query is too old to tell, I'll say, it could be diameter such as in this equation

""The Strouhal number relates the frequency of shedding to the velocity of the flow and a characteristic dimension of the body (diameter in the case of a cylinder). It is defined as {\displaystyle St=f_{st}D/U}{\displaystyle St=f_{st}D/U} and is named after Čeněk (Vincent) Strouhal (a Czech scientist).[7] In the equation fst is the vortex shedding frequency (or the Strouhal frequency) of a body at rest, D is the diameter of the circular cylinder, and U is the velocity of the ambient flow.""

However, I will say, as it now stands, that the analysis section needs a clean up, the writing does mention diameter, but, in neither of the equations does the term get used.

Sorry, I cannot help at this time.

Signed - Robin Thicke, T.I., and Pharrell Williams. — Preceding unsigned comment added by 49.184.24.3 (talk) 13:26, 25 April 2022 (UTC)

Gallery

Per WP:IG, there is no need for a gallery on this page. The policy on galleries clearly states, that a gallery "may be appropriate in some Wikipedia articles if a collection of images can illustrate aspects of a subject that cannot be easily or adequately described by text or individual images.... Images in a gallery should be carefully selected, avoiding similar or repetitive images, unless a point of contrast or comparison is being made.... One rule of thumb to consider: if, due to its content, such a gallery would only lend itself to a title along the lines of "Gallery" or "Images of [insert article title]", as opposed to a more descriptive title, the gallery should either be revamped or moved to the Commons." This gallery does not fit the policy for when a gallery should be used. Inks.LWC (talk) 17:34, 22 December 2012 (UTC)

RfC: Should the gallery in this article be removed?

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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Should the gallery in this article be removed? Inks.LWC (talk) 06:22, 20 January 2013 (UTC)

Survey

• Support - A gallery is not needed and goes against the policy WP:IG. Inks.LWC (talk) 06:25, 20 January 2013 (UTC)
• Support Without a clear rationale, we have no evidence that the gallery is essential. I like the pictures, and they illustrate the subject of the article and the various forms that this phenomenon can take (at a range of scales, in a variety of media). Refactoring into content that illustrates concepts like these (i.e. illustrating new text or table with a coherent title, rather than a gallery) might be a worthy addition. -- Scray (talk) 16:40, 9 February 2013 (UTC)

Threaded discussion

I tried starting a discussion before, but nobody (including the editor who wanted the gallery included or the appropriate WikiProjects) participated, and I'd rather not start an edit war, so I figured I'd try RfC to get more comments. Per WP:IG, there is no need for a gallery on this page. The policy on galleries clearly states, that a gallery "may be appropriate in some Wikipedia articles if a collection of images can illustrate aspects of a subject that cannot be easily or adequately described by text or individual images.... Images in a gallery should be carefully selected, avoiding similar or repetitive images, unless a point of contrast or comparison is being made.... One rule of thumb to consider: if, due to its content, such a gallery would only lend itself to a title along the lines of "Gallery" or "Images of [insert article title]", as opposed to a more descriptive title, the gallery should either be revamped or moved to the Commons." This gallery does not fit the policy for when a gallery should be used. Inks.LWC (talk) 06:25, 20 January 2013 (UTC)

While I like all the pretty pictures and appreciate the effort to collect these images and annotate them, the gallery doesn't add anything beyond the images already present, as far as explaining topic is concerned. I would support moving the gallery to the commons, to preserve the information and allow other Wikiprojects to use them; for instance, such a gallery could be appropriate in a wikibook on fluid dynamics. Mark viking (talk) 17:33, 20 January 2013 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Image depicted chimneys with spiral flutes.

"Spiral flutes are used to create an upward moving vortex to draw the exhaust gasses high above surrounding infrastructure, not to induce vortex shedding." So did I think also when I first saw spirals OUTSIDE chimneys. This PDF (text in finnish, sorry) has images saying spirals are there specificly to remove vibrations caused by winds. Text in image 4 says in (raff translation) english:"Spirals and windplates are often used as aerodynamic means to eliminate vibrations". RicHard (talk) 22:42, 20 August 2013 (UTC)

In an article from MIT reads "Driving down the road occasionally you'll notice a tall smokestack that has funny, spiral things wrapped around it. Those are the smokestack equivalents of grass [around underwater cables], to help prevent it from vibrating in wind." Q.E.D. --RicHard (talk) 23:06, 20 August 2013 (UTC)

Color Photo from ground level

Hello guys, I noticed that your photos of this effect are black and white, and from satellite images. I have a photo I will deposit here, of a rare look at the effect from the ground. The winds drove the clouds in rapidly from the flat plain, and then they started a Vortex Street when they rammed into a mountain range in the Mojave desert. I've been filming the sky most of my life and never saw anything like it. If you folks feel it would enhance your article, please use it with my compliments. Thanks- Pocketthis (talk) 17:44, 29 June 2015 (UTC)

• I put it in the article, because I believe it enhances it, as everything else is satellite black and white from above photos. If you don't like it there for some reason, remove it.-Pocketthis (talk) 15:36, 6 August 2015 (UTC)

Merge with vortex shedding?

For a while I've wonder why this article and vortex shedding are not merged. I am not an expert in physics or fluid dynamics and I may be missing something, which is why I haven't put up merge templates. I gather from these articles that as Kármán vortex street is simply what results from vortex shedding. If this interpretation is incorrect, then the articles should describe how these phenomena are different. TornadoLGS (talk) 01:16, 3 October 2019 (UTC)

I understand your concern, at this time both articles have identical scope. It should not be so. Vortex shedding occurs behind mostly any bluff body or obstacle. The vortices may originate from one side then the other, in opposite rotation directions, at a distinctive frequency and scale: in that case they are von Kármán vortices. But in the general case they may also be shed only on one side, in one direction, in clusters, at different scales, etc. This is what vortex shedding should be about. In short, I don’t think the two articles should be merged; instead the focus of vortex shedding should be moved away from the most eye-catching and most completely characterized case. Ariadacapo (talk) 11:40, 3 October 2019 (UTC)

So, if I understand correctly, a Kármán vortex street a specific and idealized variety of vortex shedding? That suggests a that it could be a section within vortex shedding, though I could see it remaining as its own article as well. Perhaps this template should go on the other article? TornadoLGS (talk) 17:48, 3 October 2019 (UTC)

I think Kármán vortex street deserves its own article: it is a very broadly studied, well-known, clearly identifiable phenomena. I don’t believe a merge is desirable, but a "generalize" template definitely would have its place on vortex shedding. Ariadacapo (talk) 07:07, 4 October 2019 (UTC)

Unclear what this sentence tries to say

I'm not sure what this sentence is trying to communicate: "This is actually the reason for which most precise sources for airfoil and channel flow data specify the reference length at a pedix to the Reynolds number" It exists in the second paragraph of the Analysis section. You'll notice the spelling check next to the word "pedix" which is the core of the problem. This word does not appear to be real. I searched the definition of the suggested word "perdix" and this also does not seem to fit the sentence (it's biological). Does anyone have any clue what the original author of this sentence was trying to get at? Pinkorulez (talk) 15:12, 7 May 2020 (UTC)

Replaced that apparently garbled sentence with "This is actually the reason for which the most precise sources for airfoil and channel flow data specify the reference length at the Reynolds number." Cosmicdense (talk) 02:55, 13 September 2020 (UTC)

Real-time MRI images.

We used real-time MRI to visualize the Vortex street. Here is a movie:

https://commons.wikimedia.org/wiki/File:Karman-Vortex-Realtime-MRI.ogg

Martin.uecker (talk) 06:16, 21 April 2021 (UTC)

Featured picture scheduled for POTD

Hello! This is to let editors know that File:Vortex-street-1.jpg, a featured picture used in this article, has been selected as the English Wikipedia's picture of the day (POTD) for August 11, 2023. A preview of the POTD can be edited at Template:POTD/2023-08-11. For the greater benefit of readers, any potential improvements or maintenance that could benefit the quality of this article should be done before its scheduled appearance on the Main Page. If you have any concerns, please place a message at Wikipedia talk:Picture of the day. Thank you! Aviafanboi (talk) 13:47, 31 July 2023 (UTC)