Talk:Pulse detonation engine

message: Let's get some pictures in here
There's a great deal of information on this subject, somewhere. I don't know enough to make the necessary changes, but yeah this needs some pictures, and an organizational cleanup wouldn't hurt. - SloverA 12:34, 2 November 2005 (UTC)

message: FWIW, the first flight of the Rutan/AFRL PDE Longeze took place at Mojave Airport today. 71.108.80.39 (talk) 03:36, 1 February 2008 (UTC)
replies: text: I've been able to confirm from another source that this is all correct.  Pictures and videos will be released soon. EMBaero (talk) 16:16, 6 February 2008 (UTC)

text: Not so - the German WWII V1 Buzz bomb used a PDE and was in mass production.  (Source - Wikipedia "V-1 flying bomb") 220.253.14.201 (talk) 00:06, 17 February 2023 (UTC)
replies: text: Uh, no. The V-1 had a pulsejet engine, per the reliable sources in that article. A PDE is an entirely different thing. BilCat (talk) 06:35, 17 February 2023 (UTC)
thread_title: First flight

message: Could someone perhaps add data about US Patent 3336754, which is the Continuous Detonation Engine?
It's mentioned as a possible future solution in VULCAN development, as seen in DARPA conference papers, page 29:
http://www.darpa.mil/TTO/solicit/BAA08-53/VULCAN_Industry_Day_Presentations.pdf
The term itself is not used anywhere on Wikipedia, although it is relevant both here and to the Rocket engine article, as some of the designs, depending on the purpose, either store fuel and oxidant, or use atmospheric air with only fuel stored.
There is little free information on the subject, most is contained in scientific publications that have to be purchased, for instance:
http://pdf.aiaa.org/preview/CDReadyMISPHST08_1877/PV2008_2680.pdf
The article mentions a rocket-like hydrogen-oxygen reaction, but from what I've gathered, a naturally aspirated CDE could be used at high mach speeds.
Someone with an extensive university library access could perhaps run a search. 
--Ssabot25 (talk) 14:01, 1 July 2008 (UTC)
thread_title: Continuous Detonation Engine

message: It seems like it would make sense to use a De Laval nozzle to help initiate the deflagration to detonation transition with fuel injection on both sides of the pinch.  Does it?  —Preceding unsigned comment added by 70.15.42.72 (talk) 01:34, 3 April 2010 (UTC)
thread_title:  De Laval nozzle to initiate DDT? 

message: I removed this: "In June 2008, the Defense Advanced Research Projects Agency (DARPA) unveiled Blackswift which was intended to use this technology to reach speeds of up to Mach 6.
 However the project was cancelled soon afterward, in October 2008. " Because  Blackswift was designed to be a scramjet. 66.127.52.57 (talk) 06:27, 14 June 2010 (UTC)
thread_title:  Not Blackswift 

message: I don't see any references to credible sources that suggest 'serious' interest in this technology by serious technology developers. This suggests that there isn't any such interests, which suggests that the article grossly oversells the idea. Citing Fox News, Popular Science, a 1952 patent, and video demonstrations of stuff is below Wikipedia standards. The DARPA reference is the best, but doesn't the hype.66.127.52.57 (talk) 06:48, 14 June 2010 (UTC)
replies: text: This is a ridiculous comment.  There has been over 50 years of research on this engine, resulting in large amounts of literature and probably hundreds of millions of dollars invested by top companies and the government.EMBaero (talk) 12:10, 14 June 2010 (UTC)
thread_title:  Not credible 

message: Google search for
::"pulse detonation wave engine" OR "pulsed detonation wave engine" -wikipedia
(the minus sign means "exclude") found "about 5,150" results. So this is a significant topic that people may want information about, whether pulse detonation wave engines exist in the real world or not. Anthony Appleyard (talk) 05:18, 11 August 2010 (UTC)
thread_title:  The 'Pulse detonation wave engine' section 

message: Another example - Grigory Adamov's sci-fi novel "Mystery of two oceans" (1938), but there was soviet submarine with pulse detonation engine.Ходок (talk) 09:57, 4 January 2011 (UTC)
thread_title: In popular culture

message: The article states: "Theoretically, a PDE can operate from subsonic up to a hypersonic flight speed of roughly Mach 5."
This claim should be backed up by a source and an explanation needs to be added. Turbojets are limited in speed because the airflow over the fan blades must remain subsonic. Ramjets have a lower bound because they compress air by forward motion and an upper bound because the combustion must be subsonic. Scramjets have a lower bound because like ramjets they compress air by forward motion, but since the combustion takes place at supersonic speeds the lower bound is even higher and there's no theoretical upper bound (barring limitations by temperature and material strength).
These limitations are explained in the respective articles. But this articles lacks an equivalent explanation. The theoretical/physical causes for lower and upper bound need to be included. 77.186.11.245 (talk) 11:14, 10 October 2013 (UTC)
replies: text: Actually, a little thought should allow you answer these questions yourself. A PDE doesn't have fan blades, so isn't limited in max speed by supersonic blade speeds like a turbojet. A PDE doesn't require airflow to compress incoming air, so isn't restricted by a min speed like a ram or scramjet. Having worked as a combustion engineer on all three systems at different times over the past 30+ years, I can tell you a PDE can indeed operate at zero speed up to hypersonic speeds.  — Preceding unsigned comment added by 68.50.90.64 (talk) 00:28, 24 September 2016 (UTC)
thread_title:  Speed regime 

message: This article states: "The basic operation of the PDE is similar to that of the pulse jet engine. In the pulse jet, air is mixed with fuel to create a flammable mixture that is then ignited in an open chamber. The resulting combustion greatly increases the pressure of the mixture to approximately 100 atmospheres (10 MPa),[5] which then expands through a nozzle for thrust." This appears to be saying a pulse jet can achieve pressure ratios on the order of 100:1 - no way. At most, a pulse jet can get maybe 2:1 - that's why you don't see them anymore, very very inefficient. Now, a PDE can achieve the 100:1 ratio, but it does that by creating a detonation wave - hence, the name. Combustion in a pulse jet is simple deflagration - no way can it boost pressure up to 100 atm.  — Preceding unsigned comment added by 68.50.90.64 (talk) 22:50, 23 September 2016 (UTC)
thread_title:  Really? 

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