Talk:Propfan

message: The histories of Propfan and Unducted fan have just been merged after a previous content merger. violet/riga (t) 21:26, 27 Apr 2005 (UTC)
thread_title: Article histories

message: There is no mention here of whether or not the engine design is actually in production use by anyone anywhere.  Anyone wanna help with that? --StarKruzr 06:47, 28 June 2006 (UTC)
replies: text: "During the 1990s, Antonov also developed the An-70, powered by four Progress D-27s in a tractor configuration; the Russian Air Force placed an order for 164 aircraft in 2003." - final sentence, and the only 'production' aircraft likely to use a propfan soon. ericg ✈ 07:21, 28 June 2006 (UTC)
thread_title: Eh?

message: I was wondering if this article should be renamed Open Rotor? This seems to be the most commonly used 'generic' name at the moment, at least for current projects. Perhaps there should be a section on the different names to help avoid confusion?  I believe Un-ducted fan was always a GE term, and UHB is more PW/RR? 192.88.212.44 (talk) 09:44, 13 August 2009 (UTC)
replies: text: Oppose - Propfan is an older term that is still used; "open rotor" is just the latest marketing term, and another will proably replace it in a decade or 2. WHatever term is coined then, it will still be called a "propfan" as clarification. There is a lot of OR in the article that needs to be cited or removed,a nd a section on the various terms used would be a good addiotion to a rewrite. - BilCat (talk) 21:54, 19 May 2010 (UTC)
replies: text: I think propfan is a fine place to keep at the article for now, as long as Open rotor and Unducted Fan are redirects/disambigs to this page. -SidewinderX (talk) 01:57, 10 June 2010 (UTC)

text: It's not in science or engineering, and that's the most I'll say in an open forum for privacy and security reasons. - BilCat (talk) 01:46, 20 May 2010 (UTC)
thread_title:  Article title 

message: Hi !: I've added a reference by Raymond Scott Ciszek, it should have had number 12, but don't know how to put it in the right place and with the right marks. Somebody willing to give a helping hand ?. Thanks, salut + Jgrosay  — Preceding unsigned comment added by Jgrosay (talk • contribs) 22:52, 11 October 2011 (UTC)
thread_title: New reference

message: For the casual reader, the difference between propfan and turboprop is unclear. From this talk page, it seems it has something to do with airspeed and the resulting blade diameter and blade count due to tip speed being kept below supersonic, but that should be better explained in the article. Perhaps a graph showing airspeed and effeciency could show why the propfan could be a good idea. TGCP (talk) 19:21, 4 February 2012 (UTC)
thread_title:  Difference between propfan and turboprop ? 

message: Reading this you would think no-one else ever worked on Propfans...!!!  — Preceding unsigned comment added by 79.71.108.94 (talk) 18:17, 24 June 2012 (UTC)
replies: text: Agree, this is a really badly written article. I would not recommend using this as a basis for understanding as 'propfan' is a very generic term - consisting of ducted and unducted. The guy talking about aircraft flight Mach number is correct as turboprops cannot venture to speeds past about 300kts whereas the propfan will operate at 400kts. The turbofan will operate at about 500kts.  — Preceding unsigned comment added by 88.104.100.238 (talk) 19:21, 13 September 2015 (UTC)
thread_title:  Once again an article that represents an entirely American view of the world! 

message: Hello fellow Wikipedians,
I have just modified 2 external links on Propfan. 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://rgfinder.blogspot.com/2011/05/arthur-cclarkes-july-202019.html
*Added archive https://web.archive.org/web/20070616153442/http://www.easyjet.com/EN/News/easyjet_ecojet.html to http://www.easyjet.com/en/News/easyjet_ecojet.html
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) 01:44, 30 December 2017 (UTC)
thread_title:  External links modified 

message: It would be very helpful for the reader to have a sectional diagram of the engine. Is there a gearbox between the propellers, or are there two power turbines? Wizzy…☎ 09:17, 19 October 2019 (UTC)
thread_title:  Cutaway diagram 

message: The Europrop TP400 looks pretty much like a propfan, with its eight curved blades. Yet it is classed as a turboprop. I think it would really help if this article could link to the TP400 article and explain why it is not a propfan. — Cheers, Steelpillow (Talk) 17:55, 17 January 2020 (UTC)
replies: text: As to why it's still a turboprop rather than a propfan (despite the number of blades, cruise speed, blade shape etc.), that's a more complicated question and you have to start comparing numbers about the aerodynamic performance, not just looking at which end the blades are on. But being single-rotation, rather than a contra-rotating fan, is a big part of that.  Andy Dingley (talk) 18:20, 17 January 2020 (UTC)

text: There's not really any reason it's classified as a turboprop other than Airbus/Europrop wanting to market the engine as a turboprop instead of propfan. It's basically the same style as the Allison T501-M78 used in NASA's Propfan Test Assessment flight test program in the 1980s, because it's also a single-rotation 8-bladed propeller, except with nearly twice the horsepower and propeller diameter. The TP400's cruise speed of Mach 0.68-0.72 is less than T501-M78's M0.80 design speed, so maybe they felt the TP400 wasn't fast enough to be called a propfan, even though the TP400's speed is still faster than turboprops have traditionally been. Also, the use of the term "propfan" has seemed to become more specific to contra-rotating fans in recent years, as more recent turboprops (or turboprop propeller replacements, like the Hamilton Sundstrand NP2000) have increased their number of blades to 6 or 8 and have incorporated sweep. D271l (talk) 07:58, 9 May 2020 (UTC)
thread_title:  Europrop TP400