Talk:Rocket engine nozzle

Citations Banner on Advanced Nozzles
As there have been citations added to this section, I'm wondering if the banner can be removed. Does anyone object due to insufficient citations? RedHotIceCube (talk) 09:02, 27 July 2009 (UTC)

No objections noted: banner was removed. --RedHotIceCube (talk) 13:03, 6 September 2009 (UTC)

Advanced Nozzles confusion
I've just updated the section and after looking back through the links have realised that there is much confusion over 'plug nozzles' (so maybe this discussion should be in that section too- EDIT: it is!!). Anyway, my understanding is that a plug-nozzle is much like an aerospike but without the base pressure component supplied by a base-bleed. Most articles I've read support this (http://pdf.aiaa.org/preview/1998/PV1998_3522.pdf) so I was wondering what evidence there was for plug nozzles and ED nozzles being confused. --RedHotIceCube (talk) 02:15, 7 November 2008 (UTC)

Merged with other articles
This article has just been merged into a new article, Rocket engine nozzles, along with Flow through nozzles, Nozzle, and Exhaust velocity. - mbeychok 03:17, 15 April 2006 (UTC)

What the? You do know they aren't only used on rockets? They're used on jet engines, and they're also used on various chemical and fluid processing systems. Don't you think you should have discussed this?WolfKeeper 04:02, 15 April 2006 (UTC)


 * WolfKeeper: On Talk:Flow through nozzles some days ago, User:MarSch said he thought that Flow through nozzles should be merged with Nozzle. I responded that I thought it was a good idea and suggested that perhaps we should also merge them with De Laval nozzle. No one objected to that idea, although admittedly it was only out there for a few days. Why did I feel it was a good idea? Because after studying the three articles, it was quite obvious that they were about 98 to 99 percent devoted to the use of nozzles in rocket engines and jet engines and they overlapped each other. Earlier today, I also queried the Village Pump (see here) as to how to merge three articles and followed their advice on how to do it. After the relevant material was extracted from the three articles .. there were only a few words left related to non-rocket and non-jet engine topics.


 * You are quite right that nozzles are also widely used in various chemical and fluid processes ... but those three articles did not discuss those uses to any extent other than a few words. What we need now is an article entitled simply "Nozzles" and devoted entirely to non-rocketry and non-jet engine uses. Yes, I was quite aware of that and I have decided to start work on such an article in the next few days (see my To Do list on my user page at User:mbeychok). Would you like to join me in that? Or would you prefer to tackle it yourself?


 * I will watch for your response here on your Talk page. Regards, - mbeychok 04:55, 15 April 2006 (UTC)


 * There's lots of ways to skin this cat. The architecture was poor to start with, but I'm sorry the current one seems to have become worse. For example, the idea that turbojet nozzles should be discussed under an article called Rocket engine nozzles is just wrong. Making bold changes is one thing, but something like this needs more thought.WolfKeeper 05:25, 15 April 2006 (UTC)


 * Wolfkeeper: Please take about 10 minutes to read the new article Rocket engine nozzles slowly and carefully. Don't pre-judge it by its title only. There is no mention at all in the article's text of turbojet nozzles .. nor of any specific rocket engine or jet engine for that matter. As you will see, the article simply has some bit of history on De Laval nozzles and otherwise it is devoted to explaining how the De Laval (or convergent-divergent) nozzle generates supersonic linear exhaust velocities and thrust.


 * Oh well, in that case, Rocket Engine nozzles is exactly the right article name then, since it doesn't mention rockets at all. Oh yeah, and linking from jet engines to an article that doesn't mention jet engines is good why?WolfKeeper 06:45, 15 April 2006 (UTC)


 * You will also see that it includes an extensive "See also" section which includes Jet engine and the Category designations include the Jet engines category. I get the impression from your comments that you feel that jet engines have somehow been given short-shrift by this article.  That certainly wasn't my intent. I simply took four overlapping articles about rocket nozzles that already existed and combined their content in a single article. I didn't think that was particularly "bold" and, with all due respect, I still don't think so.


 * It is now 11:20 PM in California and I will check here again in the morning for further dialogue. Regards, - mbeychok


 * I'm sorry, but I'm currently thinking there needs to be a revert or a major reorg of some kind; it's just not been well thought out at all.WolfKeeper 06:45, 15 April 2006 (UTC)


 * The general principle needs to be that the article name in some way relates to what's in the article. Right now, there's no connection. You've got a Rocket engine nozzle article that's not about rocket engine nozzles but contains de laval nozzle info, you've got a de laval nozzle article that's empty. The nozzle article which should be an overview you're planning to fill with stuff about fluid processing. I really truly do not understand where you are going with this; your edits seem bizarre.WolfKeeper 06:57, 15 April 2006 (UTC)


 * Wolfkeeper, please don't put words in my mouth. I did not say that the merged article was not about rocket nozzles. I said that it explained how a rocket nozzle creates thrust, and the De Laval nozzle is a prime example of that. What I did say is that the merged article doesn't mention or discuss any specific rocket engines of jet engines in any way.  Neither did the original articles which were were merged. I think the title of the merged article is perfectly apropos to the explanation of how rocket nozzle work. - mbeychok 15:08, 15 April 2006 (UTC)
 * As for your comment about linking, I did not link "from" jet engines ... I linked "to" jet engines by including them in the See Also section. Please level with me and tell me if you have yet read the entire article. I repeat again, I simply merged the overlapping contents of articles which already existed. Reverting back to the original articles won't change the fact that they don't discuss turbojets or any other jet engines.  Nor will it change the fact that they did not discuss other uses of nozzles. - mbeychok 15:08, 15 April 2006 (UTC)

I've looked at the mergers and I'm happy that flow through nozzle and exhaust velocity were merged into a bigger article. I don't think it was a good idea to redirect nozzle to rocket engine nozzle even though a large part of the text was about rocket engines. Mbeychok has already stated that he thinks there should also be a nozzle article for non-rocket engine uses so we are in agreement on that. According to the jet engine article, a rocket engine is an example of a jet engine, one which happens to be propelling a rocket. The jet engine article is also much further down the featured article path at a quick glance. It even discusses (engine) nozzles! I think it would be a good idea to consider jet engine as the main article and to try to use summary style to make everything which is too large a separate article, but also to make everything which is too small not a separate article. I have the feeling that rocket engine duplicates much of jet engine. Anyway... please comment. --MarSch 15:58, 15 April 2006 (UTC)

MarSch: I must say that I am surprised at your saying: I don't think it was a good idea to redirect nozzle to rocket engine nozzle even though a large part of the text was about rocket engines. Especially since it was your original idea to merge nozzle with Flow through nozzles. Here is your original idea:

''I think this article has a strange title. I think this could be solved by merging into nozzle which is a bit weak atm. --MarSch 14:34, 13 April 2006 (UTC)''

Have you changed your mind? - mbeychok 18:13, 15 April 2006 (UTC)
 * No, as I said I'm glad they were merged and thanks for a good job :), but as you've agreed yourself rocket engine nozzles are not the only nozzles. There was a general def at nozzle and a lot of stuff about rocket engine nozzles. Redirecting is like saying to everyone who comes to the redirect: "Hey you should really consider not writing here, but over there instead.", so I think a stubby nozzle would have been better, but this is really minor stuff, or rather it's simple to fix. --MarSch 10:31, 16 April 2006 (UTC)

Ok, I've moved lots of stuff around. I've put most of the de laval stuff back into its own article. Note that de laval nozzles are used on, not just rocket engines, but also jet engines and wind tunnels; so there needed to be a separate article for these nozzles. The 'flow through nozzle' is now part of 'de laval nozzle'. Rocket engine nozzles now largely refers out to de laval nozzle.

Nozzle now points to de laval nozzle and rocket engine nozzle and has stubs for other types of nozzle, spray nozzles, atomising nozzles, and mentions nozzles for extrusion molding and so forth.WolfKeeper 00:22, 16 April 2006 (UTC)


 * Wolfkeeper, why did you leave the three references to the exhaust velocity equation in this article when all that you left of the section was a pointer to de Laval nozzle? The references are no longer referring to anything in this article. - mbeychok


 * I've proposed to merge rocket engine into jet engine at talk:jet engine. --MarSch 10:47, 16 April 2006 (UTC)

Behavior versus behaviour
JohnnoShadbolt, both spellings are acceptable. One is the American spelling and the other is the British spelling. It is my understanding that whichever of the two was used by the original author is the one that stands. In this case, the original author used the American spelling, so I am reverting your change of the spelling. Regards, mbeychok 19:31, 18 November 2006 (UTC)

Wrong title, horrible mess!!
Obviously the title of this article is incorrect. It should be the singular, rocket engine nozzle.


 * Given that there are multiple different sorts of rocket nozzle, that's not obviously true to me.WolfKeeper 16:21, 19 October 2007 (UTC)

See WP:MOS.


 * No, couldn't see it. Which bit?WolfKeeper
 * See WP:NC. -- zzuuzz (talk) 17:00, 19 October 2007 (UTC)

So I hit the "move" button, and it woulnd't move. The page already exists, as a redirect, with a long history as an actual article before user:Mbeychok‎ did a copy-and-paste move to this incorrect title. Since it was a copy-and-past move, it did not bring the edit history along with it. Now there are two separate edit histories. If "Mbeychok" thought it needed to be plural, he could have used the "move" button and thereby avoided this mess. And this can two days after someone corrected the plural title by using the "move" button in the proper way to move it to the singular.

Does anyone know the proper procedures for cleaning up this kind of mess? I think there is one, but I don't know the details. Michael Hardy 14:53, 19 October 2007 (UTC)
 * The cut and paste move has now been fixed by merging the page histories. What is not readily apparent is where this article came from in the first place. I believe it is a merge from the articles mentioned at the top of this talk page, namely Flow through nozzles, De Laval nozzle, Nozzle, and Exhaust velocity. There doesn't appear to be much more to be done with the page histories, but when content is merged from other articles we should make a note of it for copyright reasons. -- zzuuzz (talk) 16:09, 19 October 2007 (UTC)
 * We don't need to; all material that has been legitimately added to the wikipedia is free for use for commercial or non commercial reasons, and no attribution (other than possibly to the wikipedia) is required.WolfKeeper 16:14, 19 October 2007 (UTC)
 * See WP:MERGE. -- zzuuzz (talk) 17:00, 19 October 2007 (UTC)

External links modified (January 2018)
Hello fellow Wikipedians,

I have just modified 3 external links on Rocket engine nozzle. 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:
 * Added archive https://web.archive.org/web/20080316084228/http://www.engineeringatboeing.com/articles/nozzledesign.htm to http://www.engineeringatboeing.com/articles/nozzledesign.htm
 * Added archive https://web.archive.org/web/20110616192709/http://www.aiaa.org/content.cfm?pageid=406&gTable=japaperimport&gID=5905 to http://www.aiaa.org/content.cfm?pageid=406&gTable=japaperimport&gID=5905
 * Added archive https://web.archive.org/web/20060825031851/http://trs.nis.nasa.gov/archive/00000186/01/sp8120.pdf to http://trs.nis.nasa.gov/archive/00000186/01/sp8120.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 01:41, 25 January 2018 (UTC)

Public video released of (intentional) underexpansion
SpaceX recently released a video of the initial test version of the Raptor vacuum engine hot-fire test on a ground test stand, with an (intentionally) overexpanded nozzle on the engine. Video here.

They are developing this interim engine design—where three of these engines will be used on the final version of the SpaceX Starship, the second stage of the SpaceX Starship system two-stage launch vehicle, simply because they need to initially test the vehicle and engine at sea-level—as they endeavor to design and iterate for a complete reuse of the second stage orbital ship. Thus, lots of flights of the six-engine second stage, with three Raptor vacuum engines on it, under sea-level atmospheric pressure conditions. Very interesting video footage. N2e (talk) 20:52, 25 September 2020 (UTC)

Why does exit pressure needs to be matched with ambient pressure?
Rocket are reaction engines. Why is the outside pressure relevant? Only the speed of the propellant should matter. In fact matching the ambient pressure seems like it should slow the propellant the most. Why is it?--88.100.176.55 (talk) 17:21, 7 April 2022 (UTC)

How does a rocket nozzle work?
A rocket engine uses a nozzle to accelerate hot exhaust to produce thrust. But how does it work? How does it function? Confidential Editor (talk) 14:55, 23 August 2022 (UTC)


 * Have you read the article? GabberFlasted (talk) 14:58, 23 August 2022 (UTC)