Talk:Pogo oscillation
![]() | This article is rated Start-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
Is this really a stub? It says just about all there is to say about pogo oscillations ... Richard W.M. Jones 18:53, 29 Jan 2005 (UTC)
NCIS Los Angeles
[edit]Mentioned in Rocket Man episode 67.49.180.223 (talk) —Preceding undated comment added 07:18, 13 April 2011 (UTC).
Why is it capitalized? The article notes that it isn't an acronym, and therefore shouldn't be written all-caps. But if it's named after a pogo stick, shouldn't it be "pogo"? (As opposed to a phenomenon named after the Walt Kelly comic strip.)
The Apollo 13 article links here, and it's capitalized there, too. It seems that they should both be changed.
Lets keep it as POGO that way it is unique to rocketry (liquid fuel propulsion at least) and prevents any confusion with any other future space experiments using pogo or oscillating experiments. John E Greenwood
I don't understand this explanation
[edit]Quoth the article:
- This structure was an "X" of two I-beams, with an engine on each beam and the center engine at the intersection of the beams. The center of the cruciform was unsupported, so the central F-1 engine caused the structure to bend upwards. The "Pogo" oscillation occurred when this structure sprung back, lengthening the center engine's fuel line below (which was mounted down the center of the cruciform), temporarily reducing the fuel flow and thus reducing thrust. At the other end of the oscillation, the fuel line was compressed, increasing fuel flow - causing a sinusoidal thrust oscillation during the 1st stage ascent.
I don't understand how there is negative feedback here. Let's say that the centre engine is pushing hard upwards on the X-cruciform beams. The fuel line is, as it says, compressed, increasing fuel flow. So the engine thrusts more and pushes harder upwards, compressing the fuel line further. That's positive feedback, not negative feedback surely? Richard W.M. Jones 11:41, 11 October 2006 (UTC)
From what I understand, the oscillation arises because the failure results from ever increasing oscillation amplitudes. When the structure is compressed, the thrust is increased, and therefore the structure compresses further. The structure *will* rebound eventually, and at the opposite end of the spectrum, the thrust is decreased, and therefore rebounds farther. The structure repeats the cycle, except now it has extra velocity from the previous cycle, so it compresses even further, and consequentially rebounds further. this cycle continues to increase in amplitude until the fuel is spend or the center engine fails (as in Apollo 13). —Preceding unsigned comment added by 129.107.213.6 (talk) 02:55, 1 May 2009 (UTC)
I think this account is mixing up two different cases of pogo. The fix for the S-IC was helium filled cavities in the LOX tubes leading to the outer engines to change their resonance.
The S-II stage had severe enough pogo on Apollo 13 that the centre engine shutdown early. That instance was caused by the cruciform structure it was mounted on coming into resonance and having the interplay with the J2’s cryogenic bellows (that the S-IC didn’t have to my knowledge) as described in the article. This was solved by adding the same helium spring system the S-IC used but only on the centre engine of the S-II stage.
I think the article confuses the two events together. EeekiE (talk) 22:41, 15 January 2021 (UTC)
External links modified
[edit]Hello fellow Wikipedians,
I have just modified one external link on Pogo oscillation. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
- Corrected formatting/usage for http://www.engineeringatboeing.com/articles/pogo.htm
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}
).
This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}}
(last update: 5 June 2024).
- If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
- If you found an error with any archives or the URLs themselves, you can fix them with this tool.
Cheers.—cyberbot IITalk to my owner:Online 07:48, 23 June 2016 (UTC)
A4/V2
[edit]As A4s experienced this type of mishap way before any US missilies, there should be a mention of the events here. Ciao
Pentaclebreaker (talk) 07:58, 18 March 2024 (UTC)
Start a discussion about improving the Pogo oscillation page
Talk pages are where people discuss how to make content on Wikipedia the best that it can be. You can use this page to start a discussion with others about how to improve the "Pogo oscillation" page.