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View Full Version : How fast could a propeller driven piston powered plane theoretically go ?



Jukka
03-19-2019, 01:24 AM
If you have all the knowledge and means to get there....what could it be ?

Is it M0.92 ?

I have been modelling a V-tailed "mustang" with extra hyper fast ram air effect system. It looks extremely fast. With slight v-form ie "sweep" in the wing.

Jukka
03-20-2019, 04:03 AM
Sam Bousfield and Eric Ahlstrom introduced the DART racer in 2003.

It was supposedly a M0.82 mover.

https://www.tiede.fi/s3/files/styles/medium_main_image_no_upscale/public/discussion_comment_image/sam_bousfield.jpg?itok=5ewkT35Q

Jukka
03-20-2019, 04:16 AM
Napier-Heston J.5 was supposed to go 480 mph in 1940.

https://oldmachinepress.files.wordpress.com/2015/03/napier-heston-racer-front-3-4-2.jpg

https://oldmachinepress.files.wordpress.com/2015/03/napier-heston-racer-front-3-4-2.jpg

https://en.wikipedia.org/wiki/Napier-Heston_Racer

ignomini
03-20-2019, 08:40 AM
There are various stats in various places, but the AFS lists top speed of the Tu-95 as 925 kmh, although they don't list an associated altitude. I believe it is the fastest propellor driven machine, though obviously not piston powered.

Would be very interesting to see what the Bear, Voodoo, or Strega could achieve at altitude today.

Per Air & Space:

https://www.airspacemag.com/history-of-flight/mach-1-assaulting-the-barrier-22647052/?c=y&page=2

In this article, they quote Yeager as saying, in a P-51 he achieved .81 mach in a vertical dive from max altitude. Even with mods, I expect it would be tough to get there in level flight. Yeager said Hoover was along side in a P-47 at mach .805. That I'll admit, sounds like a Yeager-y story.

CubersWrist
03-20-2019, 08:56 AM
Technical paper on the DART racer
http://aero-comlab.stanford.edu/Papers/AIAA-2000-4341-839.pdf

Jukka
03-21-2019, 12:10 AM
Do you think it would have to be a pusher ?

Jukka
03-21-2019, 12:38 AM
Does anyone have CAD file (dwg block) of a sideview of a Merlin engine ? https://en.wikipedia.org/wiki/Rolls-Royce_Merlin

Jukka
03-21-2019, 01:09 AM
Sam Bousfield and supersonic prop claim; http://www.eaavideo.org/detail/videos/general-aviation/video/1922300272001/timeless-voices---sam-bousfield

Jukka
03-21-2019, 09:32 AM
I find it very hard to draw a racer in the size of a Heston J.5 ( same length as Thunder Mustang ) using a 225 cm long engine (Merlin 61). This has now space for 300 gallons of fuel.

https://static-sls.smf.aws.sanomacloud.net/tiede.fi/s3fs-public/styles/medium_main_image_no_upscale/public/discussion_comment_image/fat_mama_55.jpg?e0BJYsQ5IatmtMjUrGO9raX50r_O9dbK&itok=AL-qtszA

Jukka
03-21-2019, 11:26 PM
FAT MAMA is 80 cm longer than Heston J.5.

Herbie's song Fat Mama; https://www.youtube.com/watch?v=iEtiaSSRGSE


The good thing about design above is the 290 gallons of fuel and ability to have a 4 metre dia prop.

It can also be made light and transonic in speed.

Jukka
03-25-2019, 09:46 AM
Some horsepowers could also be squeezed from 2 of these; https://www.hemmings.com/blog/article/cadillac-472-500-v-8/

I figure 2 x 400 hp = 800 hp.

I wonder if it was eligible for sports class ?

Jukka
03-25-2019, 10:07 AM
Chrysler HEMi looks good too;https://en.wikipedia.org/wiki/Chrysler_Hemi_engine

https://www.youtube.com/watch?v=9XJE-2KNH-Y

Jukka
03-25-2019, 11:31 AM
Spitfire M0.92 in a dive; https://en.wikipedia.org/wiki/Supermarine_Spitfire

Jukka
03-26-2019, 12:40 AM
Also M0.96 claim.

On 5 February 1952, a Spitfire 19 of 81 Squadron based at Kai Tak in Hong Kong reached probably the highest altitude ever achieved by a Spitfire. The pilot, Flight Lieutenant Edward Ted Cyril Powles,[130] was on a routine flight to survey outside air temperature and report on other meteorological conditions at various altitudes in preparation for a proposed new air service through the area. He climbed to 50,000 ft (15,000 m) indicated altitude, with a true altitude of 51,550 ft (15,710 m). The cabin pressure fell below a safe level, and in trying to reduce altitude, he entered an uncontrollable dive which shook the aircraft violently. He eventually regained control somewhere below 3,000 ft (910 m) and landed safely with no discernible damage to his aircraft. Evaluation of the recorded flight data suggested he achieved a speed of 690 mph (1,110 km/h), (Mach 0.96) in the dive, which would have been the highest speed ever reached by a propeller-driven aircraft if the instruments had been considered more reliable.[127]

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https://en.wikipedia.org/wiki/Westland_Whirlwind_(fighter)

Whirlwind with swept wing and 2/3 size with 2 x HEMIs could go fast too.

Jukka
03-26-2019, 09:55 AM
Beautiful PRSU for a LS3 V-8; https://www.youtube.com/watch?v=D2-Ajw1Rx-4

Same for a pair of HEMI 392s and you have 1060 hp out put ! Cool or what ? :thumbsup:

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2 x Falconers would deliver 1280 hp.

https://en.wikipedia.org/wiki/Falconer_V-12

Jukka
03-27-2019, 04:11 AM
Good document of an aviation IC engine.

https://www.youtube.com/watch?v=gIdXLMVP6VU

Jukka
03-28-2019, 01:54 AM
Has there ever been a flat 12 engine ?

Jukka
03-28-2019, 03:55 AM
Racing has had 10 flat-12 engines; https://www.youtube.com/watch?v=AygSW1lWVOk

Jukka
03-29-2019, 01:37 AM
Sorry wrong link...here are 10 flat 12s; https://www.youtube.com/watch?v=MZXplD_SYA4

Exhaustgases
07-04-2019, 09:27 PM
http://fighterwriter101.blogspot.com/2015/08/the-xf-88b-voodoo.html

The speed limits of the old prop planes in a dive was the wing and airframe design. Theoretically props are flying many times the speed of sound, because the compressor blades in a turbojet are very much like a propeller. The key I think is to shroud the propeller. I would love to be a part of accomplishing it.

Jukka
07-07-2019, 12:24 AM
Yes shrouded prop could give the right answer (at low altitude).

Also the feather weight solar powered aerodyne by Paul McCready went 7 x faster than on sea level at 100 000 feet altitude.

Exhaustgases
10-10-2019, 01:13 AM
Proof of concept. Prop will work at mach tip speed, and fly at mach speed. Look up the Thunderscreech.
And it flew faster than what most sites post.

Jukka
10-13-2019, 12:31 AM
Proof of concept. Prop will work at mach tip speed, and fly at mach speed. Look up the Thunderscreech.
And it flew faster than what most sites post.

Yes someone could make a proof of concept. It is basically a thrust to weight ratio question. 4500 hps and 2000 lbs should be adequate. Little bit wing sweep and good Meredith effect and everything in balance and you are good to go.

Exhaustgases
10-17-2019, 09:31 PM
I wish there was the finances so us like minded folks could work together and make this happen.

Jukka
01-31-2020, 12:28 AM
I wish there was the finances so us like minded folks could work together and make this happen.


Yes and most cost effective would be a small redesigned "Super" F2A with a R-2800.

Exhaustgases
02-17-2020, 11:14 PM
How much HP do you think would be needed?