Talk:Pulsejet

NPOV

This entire article, from the first sentence (and with the exception of the accurate technical details) reads like it was written by a bitter, angry pulsejet enthusiast who's angry that the mainstream engineering world doesn't appreciate his favorite toy enough. Accusing mainstream scientists and "most college textbooks" of lying about how awesome pulsejets are is only supportable with a great deal of actual evidence, which whoever wrote this biased screed totally failed to provide.67.194.132.240 (talk) 21:56, 21 June 2010 (UTC)

I agree. I took the liberty of deleting part of the absolutely disgusting intro. --74.192.71.213 (talk) 00:26, 5 September 2010 (UTC)

Me too. If I knew enough I would delete the whole thing and start again. I wouldn't mind the bias so much if had the good grace to set out his reasons clearly. Much of it looks like he made it up on the spot, particularly the stuff at the end about them being used for domestic heating. 81.187.148.35 (talk) 18:59, 24 January 2011 (UTC)

No, domestic heating is true. U of Reading I think it was has been working on designing no-moving-parts pulsejet stoves/generators/refrigerators for local production & use in developing nations: I may try to look up later. Field testing in Nepal a couple of years ago I think. - Egmonster (talk) 03:22, 31 March 2011 (UTC)

---

"A pulse jet engine is a very simple form of aircraft engine, falling somewhere in between true jets on the one hand and rockets on the other."

I don't like this introduction but I feel limited to express this in English. The pulse jet isn't somewhere between jet & rocket, it's simply elsewhere. A pulse jet has some kind of 2-stroke cycle : Compression & Detonation while other reaction engine works in a continuous mode.

Ericd 21:17, 9 Oct 2003 (UTC)

I agree that it is not a great sentence. I think it is only refering to complexity; trying to say that a true jet engine is complex, a rocket is simple, and a pulse jet is of intermediate complexity. I don't think a mythical "general reader" would view a rocket as simple, though, so the sentence is confusing. Rmhermen 21:33, Oct 9, 2003 (UTC)

---

I don't like these images. They have a big web site advertisement on the bottom and text. That's what the image's page is for. and they are ms paint. If I get a chance, I'll do a little research into how they work and make some nice, vector-package based diagrams. - Xgkkp 00:20, 10 Jul 2004 (UTC)

Evidence for speed record wanted

"The speed record for tethered model aircraft is 186 miles per hour, set in the early 1950s."
That value converts to 299 km/h, which is so close to 300 km/h that it makes me want to validate the information. I could not find anything online. Does anybody else have more information? Bobblewik  (talk) 12:09, 6 Sep 2004 (UTC)

This is a well known figure to model airplane enthusiasts who were active at the time (such as myself). There has always been a suspicion that multiple timers may have made coincident errors in lap counting since the record was in the form of a jump that could be accounted for by one lap and this speed has not only not ever been equaled, it has not been approached. The record was set using a simple and small airframe about half the size of the engine. Control was through a single wire (about 60 ft long) that was twisted by a pilot controlled device (a monoline control) to effect elevator control. The pilot stood in the center of a circle and controlled the elevation of the aircraft as it rotated about the center of the operating circle. Note that the FAI record for reaction motor speed is 395.64 km/hr (probably radio controlled and so without the control line drag).[1]Leonard G. 02:36, 13 August 2005 (UTC)

Thanks for the reply. I did not realise that I had stumbled upon a suspicion of lap errors. I wonder if this issue is worthy of inclusion in the article. Perhaps the FAI link is useful to others too. I will leave those decisions up to you. Regards. Bobblewik 18:10, 15 August 2005 (UTC)

acoustics

It might be nice to link the valveless version to something about acoustics, resonance, resonating tubes, etc. or add more to clarify the relationship between them if I am misunderstanding and it is supersonic explosion or something that's not really the same thing. or something. - Omegatron 22:26, Nov 30, 2004 (UTC)

Martin Wiberg

Gunter, can you provide a cite on that? I've been playing with pulsejets for yars now, own a number of books on them and their history, and I've never heard of Martin Wiberg. —Ben Brockert (42) UE News 03:26, Jan 22, 2005 (UTC)

This is actually crossreferenced from Wikipedia article: http://en.wikipedia.org/wiki/Martin_Wiberg added by user: http://en.wikipedia.org/wiki/User:Nixdorf, i suggest you ask him. --Gunter 12:35, 22 Jan 2005 (UTC)

Thanks. —Ben Brockert (42) UE News 04:58, Jan 23, 2005 (UTC)

There are no patents on engines by him that I can find (searching espacenet). DonPMitchell (talk) 13:01, 30 August 2010 (UTC)

The patent is SE 18103C1 easily searchable at the swedish patentdatabase www.prv.se. The patent describes a pulsejet driven turbine. C olsson (talk) 08:51, 13 June 2013 (UTC)

controversial uses

http://www.interestingprojects.com/ The man apparently made a cruise missile using a pulse jet for a powerplant. Total parts cost? $5k. This is at a price level that can be met by not only sub-national insurgency groups but is well within the armaments price point of many criminal gangs.

TMLutas 04:32, 11 May 2006 (UTC)

Note that he has not finished the project, and it looks like he has moved on to other projects instead. In other words, so far it's nothing but one man's dream.

212.85.68.44 10:56, 14 August 2007 (UTC)

Merge

The valveless pulse jet page should be merged with this page. Both are about the same engine, with only one difference. Most of the information is repetitive across both pages.
Another alternative is to rename this page as "value pulse jet engine" and the other as "valveless pulse jet engine". =) Jumping cheese ^Cont@ct 10:48, 18 December 2006 (UTC)

Valved and valveless PJs are, although operating on the same basic principle, very different beasts, with different designs, operating principle and history. It's not as simple as taking a valved PJ and replacing the mechanical valve with an aerodynamic valve, as demonstrated by designs such as the Reynst, the Escopette and the rear-facing intake designs. It would be like merging ordinary four stroke engines with diesels because they operate by combusting an air/fuel mix to move a piston.

The best solution, in my opinion, would be to edit it into three articles:

1. One main "Pulse jet" article, which describes the basic principles which they operate on, from a very theoretical point of view. This article would also include a very brief description of valved and valveless PJs.

2. Valved pulse jet. Description of various designs and history, focusing less on theory and more on real examples.

3. Valveless pulse jet. As #2, but for valveless engines.

I might also argue that combined intake/exhaust jets (ie the Reynst) may also deserve a separate article, as their work cycle is quite different from the other pulse jets, though still a pulsating combustion jet.

212.85.68.44 11:16, 14 August 2007 (UTC)

Sucking air

A couple of questions I think could bear answering. What governs the amount of thrust produced? Which is more significant, pulse rate or engine diameter? TREKphiler ^{hit me ♠} 00:02, 12 September 2008 (UTC)

The article repeats itself

In the first portion, the article speaks of the two types, etc, introducing the fact that there is two pipes. Later, it does the exact same thing in another section. I have no idea how to fix this... —Preceding unsigned comment added by Steventrouble (talk • contribs) 21:41, 9 September 2009 (UTC)

Valved and valveless not fundamentally different

I'm going to take exception to the claim that valved and valveless pulse jets are fundamentally different. Both use momentum in the exhaust to create a suction that draws the next intake of air. (This does not include Reynst combustors which draw air as a result of the volumetric collapse of residual hot combustion gases due to heat transfer to the cooler walls of the combustion chamber.) The net momentum in the direction of the exhaust is created as a result of the difference in the time integral of the (pressure x area) product in the forward and rearward directions during the combustion pulse regardless of whether the intake is blocked off by moving valves. The same equations apply whether the intake has a fixed minimum area smaller than the exhaust area or if the intake has flapper valves which momentarily reduce or eliminate the intake area. It is also irrelevant if the intake tubes are forward or rearward facing. Are we to write a third article if the engine uses fixed-geometry vortex diodes to rectify the intake flow? Of course not. These are all just variations of the same thing. So, make Reynst combustors a separate article, but let's avoid the unnecessary and confusing proliferation of articles for minor variations of momentum-drawn pulse jets.Magneticlifeform (talk) 05:24, 22 May 2011 (UTC)

External links modified

Hello fellow Wikipedians,

I have just added archive links to one external link on Pulsejet. Please take a moment to review my edit. If necessary, add {{cbignore}} after the link to keep me from modifying it. Alternatively, you can add {{nobots|deny=InternetArchiveBot}} to keep me off the page altogether. I made the following changes:

• Added archive http://web.archive.org/web/20151026024606/http://news.google.com/patents/about?id=vOZsAAAAEBAJ to https://news.google.com/patents/about?id=vOZsAAAAEBAJ

When you have finished reviewing my changes, please set the checked parameter below to true to let others know.

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 II}_{Talk to my owner:Online} 20:38, 27 February 2016 (UTC)