BaltACDTry uBlock a extension for Chrome.
I've been resolutely trying not to jump on the Adblock Bandwagon in what is probably a misguided and laughed-at attempt to allow Kalmbach as much technical compensation for providing the forums free as possible. It is almost at the point that I give up, since within the past three weeks or so ... seemingly from right after the mysterious lapse in being able to access the ability to post while being logged in for everything else (specifically including ad serving) ... it has become impossible not to click on one ad or another from time to time when pulling up threads. The content bounces up and down, ads bloom from overhead without warning, they pop up below and then balloon if moused over, and there is no mechanism for editing out 'mistaken clickthrough' to particular sites, or reviewing exactly what content is supposed to be "interesting" to me based on back-end extraction of the things I 'click to visit' (as opposed to things I'm tricked into clicking) or the texts of things I post. I am not deceived, I have made a point of understanding SEO evolution and the various fun abuses of cookies since the early '90s when much of the cookie handling was largely undocumented function, and I am neither unaware of or amused at heavy-handed attempts to monetize "free" resources or communities.
I'm waiting as long as I can for the promised Brave New World of the revised 'community experience', where one way or another we'll see if Kalmbach 'gets it' for this formerly-important segment of their far-flung and successful media empire concept. But I'm not comfortably accepting the devolution in the meantime without comment, either.
Somehow, I don't think that the turboprop design of the Tu-95/Tu-114 would have made the cut in Western airline service. Although the gearing worked to allow turboprop operation at higher speeds, the propeller blades were so long that the tips were supersonic (noisy).
CSSHEGEWISCHAlthough the gearing worked to allow turboprop operation at higher speeds, the propeller blades were so long that the tips were supersonic (noisy).
I wonder if the blade configuration used for the Starship would produce lower noise if scaled appropriately for 'one of four' geared turboshafts of appropriate shp?
Overmod Erik_Mag Unlike the Wright TC's, the turbine was connected by a shaft to the impeller of the first compressor stage. Can you be a bit more specific (or link to drawing(s) or specific sources?
Erik_Mag Unlike the Wright TC's, the turbine was connected by a shaft to the impeller of the first compressor stage.
Can you be a bit more specific (or link to drawing(s) or specific sources?
Source: pg 388 of "Vees for Victory!" by Daniel D. Whitney (c) 1998, Schiffer Publishing Company.
Picture a standard turbocharger with an extension shaft from the compressor end. This shaft is then geared to a fluid clutch or torque converter which then is geared to the rear of the crankshaft. The second stage supercharger was also geared to the rear end of the crankshaft. Note that a good fraction of the V-1710 production was used in P-38's where one engine was turing in the opposite direction of the other. Allison used the same cranshaft for both, flipping the fore/aft cranshaft ends between the two engines.
Development of the Allison TC was dropped partly because of the limited market for liquid cooled aircraft engines as well as the supplier of the exhaust turbine, GE, wasn't putting much effort into development.
The Wright TC had three PRT's, each of which was good for ~300 hp for a total of 800 to 900 hp. The PRT's were spaced 120 degrees around the rear of the engine and power was transmitted through a fluid coupling and then some sort of 90 degree gearing to the crankshaft.
The "low sfc" project for the R4360, was the Variable Discharge Turbine. The gist was that "throttling" was done by using a nozzle to constrict the flow from the exhaust turbine. Some rather spectacular claims were made for range and service ceiling improvements for the B-36, but the increase in cooling fan power negated much of that. Would have been interesting to see what it could have done in the Republic Rainbow.
Liquid cooled engines will often have a low sfc as the liquid cooling allows for lower cylinder head temperatures which then allows for a higher compression ratio. Note that the Allison V-1710 had 4 valves per cylinder.
Erik_MagPicture a standard turbocharger with an extension shaft from the compressor end. This shaft is then geared to a fluid clutch or torque converter which then is geared to the rear of the crankshaft. The second stage supercharger was also geared to the rear end of the crankshaft.
The problem is, try as I might, I can't find any reference that says the exhaust turbine used on the compounded V-1710 had an actual compressor installed on it; one reference says the turbine came from a turbosupercharger design but was explicitly reduced to producing torque only.
I will now have to find a copy of Vees for Victory and see what the detail actually is. This is not so bad as I can get the poop on the yet more interesting V-3420-B (and the possibilities of its turbocompounding!) in the same place...
For those of you who are engine-porn aficionados, here is something of interest: the magic starts around 3:56. The key here is to listen for the turbine lag as the power comes on and off...
https://www.youtube.com/watch?v=wVmMd2BnbJ4
Overmod: Found the engine starting sequence very reminding. Have no experience of the 3350s. For first start of R2800 was 5 complete rotations first ( 15 blades ) and for 4360s again 5 rotations ( 20 ) blades. Then ignition boost, prime, throttle, mixture. You always knew who was a new Captain or first officer on the Convairs or engineers on the Connies by the backfires you heard when starting those engines! It was a co-ordination exercise that just had to be learned. I was lucky. Had more than one Captain who would never start an engine but just count the blades.
You have no idea how busy the flight engineer on a Connie was during starts. In fact an engineer was considered not baptized until his first time sliding off the wing of a Connie while dip sticking the fuel tanks. Happened a lot during winter times. There were some ground persons who would follow you while you dip sticked.
Bringing this thread back for a bit.
Remember the B-17 crash in Windsor Locks CT back in 2019? I found a video giving the "whys and wherefores" of the event. It's a little bit dry, runs about 20 minutes or so, but does a good job explaining what went wrong and why.
"The holes in the Swiss cheese all lined up."
https://www.youtube.com/watch?v=y3p-hGR3ZyY
Flintlock76Bringing this thread back for a bit. Remember the B-17 crash in Windsor Locks CT back in 2019? I found a video giving the "whys and wherefores" of the event. It's a little bit dry, runs about 20 minutes or so, but does a good job explaining what went wrong and why. "The holes in the Swiss cheese all lined up." https://www.youtube.com/watch?v=y3p-hGR3ZyY
Never too old to have a happy childhood!
The code name for Hitler's train was, believe it or not, Amerika !
BEAUSABRE The code name for Hitler's train was, believe it or not, Amerika !
Hermann Goering had a train of his own, called "Asien," or "Asia."
Have a look:
https://www.youtube.com/watch?v=nMc3Kw9aNEs
Hermann sure liked to live large, didn't he? I've seen the Blue Goose at a show in Michigan. It's unrestored and painted a blue metallic with one-inch thick windows, one of which has a bullet mark. Likely someone from the 101st Airborne who captured the car and wanted to see just how bullet proof it was. There are stencils from the 101st on the bumpers too. Also, the car at 6:06 (and later on) is a 1937 Buick convertible sedan.
Here's a good one with Mustangs:
https://www.youtube.com/watch?v=AmShtLOmwrA
54light15 Hermann sure liked to live large, didn't he? I've seen the Blue Goose at a show in Michigan. It's unrestored and painted a blue metallic with one-inch thick windows, one of which has a bullet mark. Likely someone from the 101st Airborne who captured the car and wanted to see just how bullet proof it was. There are stencils from the 101st on the bumpers too. Also, the car at 6:06 (and later on) is a 1937 Buick convertible sedan.
Dr. Felton's got a video on "The Blue Goose" as well.
https://www.youtube.com/watch?v=sAf1fYawXNo
Interesting newsreel featuring those RAF Mustangs! I wonder if they still had the Allison engines or had been upgraded to the Rolls Royce Merlin by that time?
Those would have been Allison powered- notice the air intake above the prop-the later Merlin powered versions didn't have that.
You may be interested in a website called "Bring a Trailer" which is an auction site for vintage and newer cars. They had a survey a year or two ago that asked people what was the best V-12 ever made. The consensus was, the Packard-built Merlin. I totally agree with that.
54light15 They had a survey a year or two ago that asked people what was the best V-12 ever made. The consensus was, the Packard-built Merlin.
Damn right. Nothing succeeds like success, right?
Flintlock76Damn right.
Although I confess it would have been interesting to see how the Allison engine might have fared if it had been properly supercharged for actual use in the aircraft it was intended for...
I do think the 12-567/645 is up there too, and perhaps overall the 12-710 and its GEVO counterpart. Just in the 'attacked' and not 'attacking' column...
OvermodAlthough I confess it would have been interesting to see how the Allison engine might have fared if it had been properly supercharged for actual use in the aircraft it was intended for...
Oh they tried, from what I've read they really tried, but it just didn't work out.
No matter, for certain applications the Allison worked out just fine, for example the P-38's and P-39's used in the Pacific where high-altitude performance wasn't a must, or the P-39's shipped to the Soviet Union as Lend-Lease aid. The Russians made very good use of those Allison engined P-39's as low-level ground attack aircraft. Russian pilots liked those P-39's, a lot!
Overmod And damn right that it was the Packard, and not the Rolls-Royce, version of the engine that was cited. There are reasons...
And damn right that it was the Packard, and not the Rolls-Royce, version of the engine that was cited. There are reasons...
Thanks to Chris / CopCarSS for my avatar.
Murphy Siding Overmod And damn right that it was the Packard, and not the Rolls-Royce, version of the engine that was cited. There are reasons... What are those reasons? Weren't they building off the same specs and blueprints?
What are those reasons? Weren't they building off the same specs and blueprints?
I think one set of blue prints was SAE and another was British Standard.
From what I've learned, the Packard people used the RR plans and made improvements wherever they could both for performance and production. They had the capacity to build them quickly and reliably, better than Rolls-Royce could do. Remember that Packard was a mass production plant and Rolls built every car pretty much to order and they were not set up to mass produce like the American automobile companies could do.
Flintlock76 Overmod Although I confess it would have been interesting to see how the Allison engine might have fared if it had been properly supercharged for actual use in the aircraft it was intended for... Oh they tried, from what I've read they really tried, but it just didn't work out.
Overmod
One reason is that the Allisons were more conservatively rated in that USAAF regulations required that the engine produce rated power for a longer period of time than the RAF. The book I have on Allison engines also stated that Allison was behind RR is dealing with backfires - not preventing them but limiting damage caused by the backfires.
Note that the P-38 DID have lots of high altitude power, but it was the turbocharged version of the Allison engine. A P-51 with a turbocharged Allison would have had 1/3rd more range/combat radius than the Merlin equipped P-51. The ultimate Allison would have been the turbo-compound with an sfc even lower than the Wright turbo-compound used on the DC-7s and later Connies. Take-off power would have been close to 3,000HP.
The Allison had fewer parts, something like 7,000 versus 12,000 for the Merlin and also had substantially fewer unique parts.
BALT:
The parts in the Packard built Merlins were required tobe interchangeable with the parts for the RR built Merlins, so the Packard built Merlins did not use SAE hardware.
As I recall, the turbocharger on the P38 took up a lot of space on top of each nacelle/tail fork. . It would have needed a large bulge on a P51, which was a much smaller plane.
YouTube's "Greg's Airplanes' has exhaustive discussions on many WW II fighters on both sides.
https://www.youtube.com/watch?v=mzQuq2FHdeE
charlie hebdo As I recall, the turbocharger on the P38 took up a lot of space on top of each nacelle/tail fork. . It would have needed a large bulge on a P51, which was a much smaller plane.
I'm pretty sure that the nacelles on a P-38 were no wider than the fuselage on the P-51 as they were a snug fit on the V-1710. OTOH, I don't think there was any room between the back of the engine and cockpit, so a turbocharger installation would probably been behind the pilot. There was some work done to fit turbochargers on P-63's which was made a bit easier with engine behind the pilot (as in the P-39), but still required lengthening the fuselage.
A few engine tidbits:
The lateral outline of the Merlin engine was determined by pushing a seated draftsman up against a wall and drawing the outline of said draftsman asthe engine didn't have to be any smaller than the pilot.
The supercharger on large non-fuel injected aircraft engines was intended to be a homogenizer as well as a compressor. Without it, the fuel to air ratio could vary substantially between cylinders with all sorts of adverse effects.
The most sought after Merlins for air racing are the "transport" Merlins produced after the end of the war. These were designed for the Lancastrian airliners and the modifications were based on experience with war time Merlins.
The P-82 Twin Mustangs used Allison engines as the USAAF was tired of spending $6,000 in royalties for each Packard built Merlin out of the $20,000 paid for each Merlin towards the end of the war.
Leo_Ames I wonder what made for the best train strafer in the European theater? I imagine it's a race between the USAAF P-47 and the RAF's Hawker Typhoon and Tempest.
I wonder what made for the best train strafer in the European theater? I imagine it's a race between the USAAF P-47 and the RAF's Hawker Typhoon and Tempest.
Leo_Ames ;) At last, we have an answer (at least in simulation): https://www.youtube.com/watch?v=MGFSo6OhMcE
;)
At last, we have an answer (at least in simulation): https://www.youtube.com/watch?v=MGFSo6OhMcE
Well, since this Warbird thread has come roaring back to life how's about a little celebratory music?
https://www.youtube.com/watch?v=cNVVoH9-QH0
Flintlock76Well, since this Warbird thread has come roaring back to life how's about a little celebratory music? https://www.youtube.com/watch?v=cNVVoH9-QH0
Ironic that Werner Klemper of Hogan's Heros fame as Col. Klink was cast as a German General in this opening scene.
BaltACDIronic that Werner Klemper of Hogan's Heros fame as Col. Klink was cast as a German General in this opening scene.
Well, actually no. Werner Klemperer wasn't in "Battle of Britain." Those are all German actors although one has a resemblence to Werner.
Flintlock76 Well, since this Warbird thread has come roaring back to life how's about a little celebratory music? https://www.youtube.com/watch?v=cNVVoH9-QH0
Great opening titles sequence. The "Aces High" march, designed to resemble a traditional German march, was actually written by British film composer Ron Goodwin.
You want warbirds? You want music?
https://www.youtube.com/watch?v=EAVejLjXVdw
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