Talk:Eddy (fluid dynamics)

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 25 February 2020 and 8 May 2020. Further details are available on the course page. Student editor(s): Tannerhowe. Peer reviewers: Huiqi w.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 20:09, 16 January 2022 (UTC)

Peer Review

(moved from user talk page)

Things that were done well:

• The images are very helpful for understanding what an eddy is/what it looks like
• I like that it's pointed out that eddies are not a property of the fluid, and that it can be used as a tool (to promote good fuel/air mixing).
• Tying the Reynolds number into the article and talking about the transition point and critical number is really helpful.

Things to improve

• Where it says (see image) under the mesoscale ocean eddies section, it's a little unclear what image is meant. It might be better to say, an example of this is shown in.. and describe the image.
• Make sure everything that has an existing article is linked. Ex: all instances of Antarctic Circumpolar Current. (This is something I need to do in my article too)
• The article as a lot of really good information but I think more thought could be put into how the information is organized. For example, Mesoscale ocean eddies is a really interesting example of eddies and it's a very thorough section, but I'm not sure if that should be the first section because it's a very specific topic not important to every reader.
• I would also like to see more information in the engineering specific section (of course I'm biased). Example: maybe some pros/cons of turbulent flow in industry, like how it could increase heat transfer if that's what you want or how it could result in energy losses.

Clarefc (talk) 22:59, 27 February 2017 (UTC)

Peer Review

-The majority of the article is well cited.

-Very interesting material presented in a good fashion.

-Could you get a photo of a river flowing past a rock to visualize what is being said in the first paragraph?

-Reword Vortex paragraph, for example “Another possible type of turbulence is the vortex. This concept is similar to the eddy, however it applies to gases instead of liquids. In this case, there is no void created, only an area…” It was a little difficult to grasp exactly what the paragraph was saying. Also cite this section.

-Is the entire “Mesoscale ocean eddies” section information gathered from the same source [2]? If not, cite more often.

-Is the Critical Reynolds number always 2000, or is this just for certain cases? Also this needs citation.

-Can you expand on what solutions are being developed/have been developed to remedy turbulent flow in the arterial tree? This section seems incomplete.

-In the industrial processes, can you give an example of how it is used to thoroughly mix fluids and increase reaction rate. It will have a greater impact this way.

-When defining the variables for the Navier-Stokes equation, write the entire definition in the equation format, to maintain consistency with how you defined variables after previous equations. Llavecch (talk) 08:00, 16 February 2017 (UTC)

{Hey, thank you for your input! To optimize space, I’m going to address points made in your review that I either have difficulty implementing or have a differing opinion on. If not addressed, the assumption is that I agree entirely or don’t have an explanation for the mistake and will be making the appropriate adjustments.

Bullet Point 3 – I agree there should be a photo of this, but I’ve been having difficulty uploading third party images that aren’t provided in wikipedia’s inventory of graphics.

BP 5 – That section was there originally and so I have treated it more as a back burner project, especially seeing as how it’s about a specific type of Eddy formation rather than just general info on eddy fluid dynamics. But from what I have gathered, yes, the author used only one source and the section needs drastic improvement.

Last BP – I’ve had some trouble playing with the formatting of these articles, especially regarding graphics and math sections. I don’t quite understand your last observation on maintaining consistency with the variables. Can you elaborate a little more on that?

Again, thank you for your input on the article! Edits and Revisions will be made soon. Nlhw13 (talk) 19:57, 25 February 2017 (UTC)}

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Nlhw13. Peer reviewers: MissAndrea, Clarefc, Llavecch.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 20:09, 16 January 2022 (UTC)

Article Evaluation

So far the content of the article is heavy with descriptions, but little data or related equations have been included. The section on Mesoscale Ocean Eddies is written well, but there aren't nearly enough citations to support the arguments/descriptions made. The section on the fundamentals/math/engineering of eddies and fluid dynamics is severely lacking. Pictures/images provide a decent image/pathway of an eddy, but ultimately the article needs many more cited sources and significant development in the science/math behind eddies and fluid dynamics. Nlhw13 (talk) 04:03, 13 January 2017 (UTC)

All calculations for Eddy size/speed relate back to turbulent flow equations. Should these equations be added to this page as well or is a link to the turbulence page enough? I guess that also brings up the issue of all the different applications/scenarios in which eddy flow is relevant (mixing fluids, ocean currents, blood flow, etc.) and whether each topic should be discussed in detail here or linked to another already fleshed out article. (Apologies if this is not the proper medium through which to bring up these questions/concerns).Nlhw13 (talk) 09:11, 2 February 2017 (UTC)

Note to add equations/info on wall shear stress and how it relates to eddy/turbulent fluid flow. Nlhw13 (talk) 21:41, 12 February 2017 (UTC)

Note to use this source http://www.fem.unicamp.br/~im450/palestras&artigos/ASME_Tubulence/cds13instruct2.pdf for more equations relating to turbulent flow. Nlhw13 (talk) 23:09, 12 February 2017 (UTC)

Note to add more information about computational fluid dynamics.Nlhw13 (talk) 23:41, 12 February 2017 (UTC)

Peer Review

Hello Nlhw13,

For the purposes of this class, I moved my peer review from your sandbox to here.

Your article seems off to a good start! -I would put in a lead section that gives readers a good grasp of the whole article / what eddies are all about. -You could add in research and development in the lead. -The headings are in a logical order. -I would add more sources for each research and development topic so that the article has balanced info on research that's been done (e.g. on hemodynamics or industrial processes). -The tone is encyclopedia/objective, and the spelling/grammar is fine. -One last thing I recommend doing is finding another source that backs up the source "Why are golf balls dimpled" (from a textbook or journal article) just to be on a safe side. MissAndrea (talk) 03:52, 14 February 2017 (UTC)

MissAndrea (talk) 19:32, 25 February 2017 (UTC)

Vortex

Is it synonym? Can anyone please explain the difference. Infovarius (talk) 19:58, 14 August 2021 (UTC)

Yes, I can explain the difference. I apologise that it has taken 10 months for someone to acknowledge your question. On Wikipedia an eddy is what can be observed in the unsteady motion of a fluid. Eddies usually can only be observed in a liquid at its interface with a gas, or in a colloid such as cloud at its interface with clear air. In contrast, on Wikipedia, vortex motion is defined as the steady motion of a fluid along a curved path. In the steady motion of a fluid there defined to be only linear (or uniform) motion and vortex (or cyclic) motion. In the absence of linear motion there is “a vortex”, a purely circular motion with every fluid element following a streamline that is precisely circular. Whether the velocity along a streamline shows a decrease (or increase) with increasing radius confirms that the motion is a free vortex (or forced vortex.) The concepts of the vortex, and vortex flow, serve an important role in the science of fluid dynamics. For example, the flow of air around a lifting airfoil can be shown to consist of a vortex (the bound vortex) and a uniform flow. The lift generated by the airfoil is directly related to the strength of the vortex. The concept of the eddy is never used with this degree of definition and mathematical rigor. Dolphin (t) 00:52, 26 June 2022 (UTC)

https://books.google.de/books?id=9QjuCAAAQBAJ&pg=PA170&dq=eddy+vs+vortex&hl=de&sa=X&ved=2ahUKEwjk_YvjgLr4AhUPSPEDHR7iBFIQ6AF6BAgGEAM#v=onepage&q=eddy%20vs%20vortex&f=false "A vortex is an eddy or swirl of fluid", both articles should be merged. Biggerj1 (talk) 17:15, 19 June 2022 (UTC)

Oppose Infovarius and Biggerj1 See my reasoning immediately above. The Google Books dictionary may define eddy and vortex as synonymous but Wikipedia and most specialist scientific and engineering sources do not. Wikipedia defines the free vortex and the forced vortex with a mathematical rigor that is never used in the explanations for eddies. The concept of the vortex in steady flows plays an important role in quantifying the speeds and pressures at different points around engineering bodies such as airfoils, wings, propellers, etc. Dictionaries do not provide for this depth of application of words and concepts so it is not surprising that the dictionary explanations of vortex and eddy are similar whereas an encyclopaedia distinguishes strongly between the two. Dolphin (t) 01:06, 26 June 2022 (UTC)

There is more discussions here: https://www.researchgate.net/post/What-is-the-difference-between-a-vortex-and-an-eddy Biggerj1 (talk) 08:06, 26 June 2022 (UTC)

Comment An eddy is a movement of fluid that deviates from the general flow of the fluid. A vortex is a kind of eddy that produces such deviation. But there are other types of eddies that are not simple vortices. Encyclopedia Britannica[1] gives the example of a Rossby wave, an undulation that is a deviation from mean flow, but doesn't have the local closed streamlines of a vortex. So eddy is the more general concept. This is why folks talk of large-eddy simulations of turbulence and not large-vortex simulations--fluid movement in turbulence can have far more complex behavior than simple vortices. Hence I think identifying an eddy as equivalent to a vortex would be incorrect. --{{u|Mark viking}} {Talk} 09:26, 26 June 2022 (UTC)

Thank you for the explaination! What about adding your statement to the introduction of eddy? "An eddy is a movement of fluid that deviates from the general flow of the fluid. An example for an eddy is a vortex which produces such deviation. However, there are other types of eddies that are not simple vortices. For example, a Rossby wave is an eddy which is an undulation that is a deviation from mean flow, but doesn't have the local closed streamlines of a vortex. " Biggerj1 (talk) 06:17, 27 June 2022 (UTC)

I added this to the introduction of the article Biggerj1 (talk) 08:46, 17 July 2022 (UTC)  Biggerj1 (talk) 08:46, 17 July 2022 (UTC)

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