This may have been covered before, but is always worth updating from time to time as more data becomes availible.
Question 1)
The Armstrong Whitworth Apollo was fitted with Mamba engines, in an early photo four-bladed propellors are on the inner engines and three-blades on the outer. Would this improve performance, if fitted on another four engined aircraft?
I don't think there is a universal formula indicating this would beneficial. Each aircraft is unique, and if I understand it correctly on the Apollo it was more of a stability issue, that more blades on the inner engines helped improve, so perhaps not just a "performance" increase in the traditional sense, but perhaps better specific thrust at certain settings. Another aircraft with differing propellors (and differing number of blades) was the PB2 Coronado, with 4 shorter blades on the inner engines, 3 longer blades on the outers. This was to ensure proper clearance between the blade tips and the fuselage, with the added benefit of thrust reverse for surface maneuvering.
Plenty of aircraft do just fine with four, 3 bladed props, or four 4 bladed props (or 2, or 6, etc).
Many factors go into choosing the propeller (and the number of blades). Engine specs, clearance, angle, airflow, size, weight, RPM, desired flight characteristics, cooling, etc.
Having different props on the same aircraft complicates synchronization, maintenance, etc. So unless there is a specific reason for needing different props on the same aircraft like ground or fuselage clearance, correcting a specific flow pattern, increasing thrust on a certain set for stability issues, etc I would not think the benefits would be universal.
Thanks,
Question 2)
Has there ever been a gas turbine engine fitted to an aircraft?
Question 3)
Most airliners have the engines under the wings on pylons, some like the VC10 or Trident had a combination with engines at the rear and under the wings. Have they ever been placed at the front of the wings or just past the wings on pylons?
Question 4)
Submarines can launch missiles from under the sea, has this method been used in a jet powered sub?
Question 5)
The mission to Mars is still going ahead, have they worked out how to get back to Earth? Are there no planets closer to land on and explore?
Question 6)
I can usually hear an aircraft before I can see it and yet the speed of sound is slower than the speed of light ?
Question 7)
Digital camouflage patterns have been seen used by the USA military. Do other countries use it, or is it better than the current patterns?
Quote from: McColm on November 08, 2014, 11:04:59 AM
Thanks,
Question 5)
The mission to Mars is still going ahead, have they worked out how to get back to Earth? Are there no planets closer to land on and explore?
Part 2- No, save the Moon. Part 1, some plans have it a one way trip establishing a colony, others have a round trip, creating fuel for the lander locally
Question 2) Er, perhaps you could re-post that. Frank Whittle and Hans von Ohain did it a LONG time ago......
Question 3) If you look from the side many aircraft, especially large airliners, have the pylon mounted engines actually forward of the leading edge. The DC10 and 777 are cases in point.
Question 4) Are there any jet powered subs?
Question 6) You have to be looking in EXACTLY the right direction to see it, whereas the sound arrives at your ears without too much directional information.
Q5. Mars is also the planet with surface conditions closest to earth. All the others are mostly gas, have poisonous/corrosive atmospheres, molten surfaces or are frozen balls of ice so cold it snows methane.
Q4. Submarines are hunted with SONAR therefore the most important characteristic of any design is low levels of noise while operating. A rocket engine (you could also use a jet but it would either need a big snorkel or a really huge supply of compressed air) would create a lot of noise as the exhaust boiled the water.
Q6. If the wind is in the right direction you can hear further than you can see. Your ears have better resolution than your eyes.
2: Uhh, yes? You talk about two of them in Q.3...
4: There are no "jet-powered subs". Jet engines need air to run, something in rather short supply when under water... :rolleyes: Submarines are nuclear powered or diesel-electric (there may be a few one-off freaks out there).
5: The proposed privately-funded "Mars One" mission is one-way only. They won't be coming back. There are no other rocky planets that are remotely reachable that are plausible targets for a manned mission. Mercury is tiny, and very close to the sun so very hot. Venus is even worse, due to it's incredibly dense atmosphere which traps heat. Earth is next, then Mars. After that there's a very big gap, and then the gas giants. Some of the moons of Jupiter and Saturn may be targets for manned missions eventually. Beyond those are the dwarf planets, which are very small, very cold, and very, very far away.
6: You can see an airliner at 30,000 feet from much, much further away than you'll ever hear it. Go and read up on how sound travels, as opposed to the way light travels.
7: Yes, plenty of countries have introduced digital camouflage patterns. Canada actually did it before the Yanks.
Is this by any chance a satire of my questions?
No satire intended, genuine questiones that have yes or no explained in words that I can understand
Question 8)
Has anyone considered using a flying boat/seaplane in the AEW role?
As a Whiffer the Shorts Sunderland springs to mind as a possibility, as the rotor dome can be mounted above the fuselage or fixed array .
Question 9)
The USAF and the USNavy deploy dedicated EW aircraft. So how come the RAF and the Royal don't follow suit? There was a Canberra EW training aircraft used but no dedicated EW Canberra deployed.
2) gas turbine = jet ... you've probably noticed quite a few of them flying around recently. ;)
3) Kit answered this one.
4) I don't know if any exist (I doubt it) but you could have electric motors running turbine blades to propel a sub but, as stated, a jet engine needs lots of air & runs very hot, with a lot of exhaust gases to get rid of.
5) Basically, the answer is "yes" - Venus. Venus, however, is not conducive to any length of survival for Human explorers (Venus (http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Venus_compared_to_Earth)), whether in suits or not. (minimum Earth-Venus distance = 43,160,000 km; minimum Earth-Mars distance = 52,600,000 km) The distance to Jupiter is sufficiently great that, even at its closest, it's further away than Mars at its most distant.
6) Again, Kit answered this one.
7) No idea, see pyro-manic's answer.
Still working on 8 & 9.
8] By the time that AEW had reached a practical level of operation flying boats were already on the way out. The Grumman TBM-3W Avenger was the first production practical AEW aircraft and that entered service in mid-1945. The USN used big scanners inside airships after that, before both the USN and USAF took delivery of the Super Connie AEW aircraft in the early 50s. By then the only flying boats in service were the USN's Marlins and the RAF's ancient Sunderland 5s.
9] Perhaps the RAF figured that the pylon mounted underwing pods, the BOZ109 for example, were good enough for their planned operations?
Quote from: McColm on November 27, 2014, 12:40:44 PM
Question 8)
Has anyone considered using a flying boat/seaplane in the AEW role?
As a Whiffer the Shorts Sunderland springs to mind as a possibility, as the rotor dome can be mounted above the fuselage or fixed array .
Question 9)
The USAF and the USNavy deploy dedicated EW aircraft. So how come the RAF and the Royal don't follow suit? There was a Canberra EW training aircraft used but no dedicated EW Canberra deployed.
An AEW/AWACs conversion of the SARO Princess was proposed ca. 1956.
While question 2) has already been addressed repeatedly, I'd just like to add that in addition to 'jet' airplanes that are powered by turbojets or turbofans there are also propeller airplanes driven by turboprop engines, all of which belong in the gas turbine family, so yes, it's been done.
As for the statement in question 5) that the "mission to Mars is still going ahead", I can only assume that you are referring to the Mars One concept, which currently mainly appears to consist of marketing efforts, as opposed to any of the actually ongoing Mars missions, such as the ISRO Mars Orbiter Mission Mangalyaan or the NASA Mars Atmosphere and Volatile EvolutioN Mission (MAVEN) Mars Orbiter. Pretty good summaries and assessments of the Mars One company as well as the overall project and its merits (or lack thereof) can be found at http://en.wikipedia.org/wiki/Mars_One and https://medium.com/matter/all-dressed-up-for-mars-and-nowhere-to-go-7e76df527ca0. As for whether they have "worked out how to get back to Earth", they haven't and they won't, since the mission architecture is explicitly and deliberately based on a one way trip to establish and grow a colony without a chance for a return ticket. But to paraphrase a more than two decades old statement of then Secretary of the US Air Force Sheila Widnall that she made with respect to space launch studies, "the Earth is covered by two thirds water and one third Mars mission studies", and the vast majority of crewed mission studies did indeed address the question of how to get back to Earth in more or less extensive detail. Fairly good introductory overviews over the various alternatives for getting humans to Mars and back can be found at http://history.nasa.gov/monograph21.pdf, http://webserver.dmt.upm.es/zope/DMT/docencia/motores-cohete/informacion-complementaria/Viaje%20a%20Marte.pdf, and https://engineering.purdue.edu/AAE/Research/Groups/longuski/Software/NOMAD/Papers/ComparativeAssessment.pdf, while NASA's most recent Mars Design Reference Architecture is documented at http://www.nasa.gov/pdf/373665main_NASA-SP-2009-566.pdf, http://www.nasa.gov/pdf/373667main_NASA-SP-2009-566-ADD.pdf, http://www.nasa.gov/sites/default/files/files/NASA-SP-2009-566-ADD2.pdf, and http://www.nasa.gov/pdf/373669main_2008-12-04_Mars_DRA5_Executive_Summary-Presentation.pdf, whereas ESA's corresponding effort is described in http://emits.sso.esa.int/emits-doc/1-5200-RD20-HMM_Technical_Report_Final_Version.pdf, so the question how to get to Mars from Earth and back again has already been answered repeatedly.
Hope this helps,
Martin
2) could that be a ""natural"" gas turbine you're asking about, there are hundreds of those operating around the world, albeit they're usually mounted in front of a huge electric generator and fixed to the ground ---- they're called co-generation plants (I did quite a few drawings of the huge heat exchangers that the exhaust runs through some years ago)
3) there was this one which was unusual http://en.wikipedia.org/wiki/VFW-Fokker_614
Quote from: kitnut617 on November 28, 2014, 02:13:10 PM
3) there was this one which was unusual http://en.wikipedia.org/wiki/VFW-Fokker_614
Oh yes, the VFW614, cracking aeroplane. :thumbsup:
I flew in one from Copenhagen to Bremen once, and demanded a seat next to the engines, just because it looked SO weird looking out the window. ;D
Just happened to notice the link to this in the VFW 614 wiki article;
Honda HA-420 HondaJet (http://en.wikipedia.org/wiki/Honda_HA-420_HondaJet)
Quote from: Old Wombat on November 28, 2014, 04:00:40 PM
Just happened to notice the link to this in the VFW 614 wiki article;
Honda HA-420 HondaJet (http://en.wikipedia.org/wiki/Honda_HA-420_HondaJet)
Going WELL off thread, I notice the bit about Honda's legal action against FlightGear for including the HondaJet in their simulation.
Are they mad? There's no such thing as bad publicity!! How come they didn't act against Flight Magazine or even Wikipedia for even mentioning the aircraft?
They obviously got McDonald's-Disney Disease with their move to US-based manufacturing. ;)
On the jet,rocket subs the uk at least is no longer using a conventional prop. They are now using a stator is basically a front fan disk from a jet engine inside a cowling. The caterpillar drive from red October a jet engine for subs is a real system but the power needs at the moment are off the scale
Question 4: I don't know of any manned rocket-powered subs, but it's certainly possible in theory since there have been a number of rocket-powered torpedoes and non-encapsulated underwater-launched missiles. The Russians have a rocket-powered torpedo called the Shkval which has two rockets: a big one at the back to push it along and a small, forward-facing one at the front which creates a "sheath" of gas around the body, thus reducing friction with the water. You could make a manned vehicle using the same principle, but for what purpose? Most practical underwater missions demand stealth and/or endurance, rather than speed.
:blink:
A jet powered rescue sub would be ideal. :thumbsup:
Quote from: lenny100 on November 29, 2014, 03:19:56 AM
On the jet,rocket subs the uk at least is no longer using a conventional prop. They are now using a stator is basically a front fan disk from a jet engine inside a cowling. The caterpillar drive from red October a jet engine for subs is a real system but the power needs at the moment are off the scale
Not exactly the
pump-jet propulsors have been around for some time and prior to use on UK and US
subs they were used on torpedoes.
Quote from: McColm on November 29, 2014, 08:18:07 AM
:blink:
A jet powered rescue sub would be ideal. :thumbsup:
Not really: it'd be blind. The Shkval only has inertial guidance because sonar doesn't work through the gas sheath.
Question 10)
The Sky Dreadnought as seen on TV over parts of Russia. Built by the Americans as the world's deadliest weapon delivery system. As long as three aircraft carriers and can travel up to 10,000mph. Anti-gravity propulsion. Fact or fiction?
11)
British Airways sometimes turn over the engines of Concorde kept at Heathrow Airport. Could the SR-71 Blackbird ever fly again?
12)
I've seen photos of 'time travel/travelers', if you could travel back in time . What year would you choose and why?
12. 1066 to witness the Battle of Hastings and solve, once and for all what happened to Harold. Was it an Arrow in the eye or did he survive the battle and was hunted down?
Quote from: McColm on December 24, 2014, 01:34:06 PM
Question 10)
The Sky Dreadnought as seen on TV over parts of Russia. Built by the Americans as the world's deadliest weapon delivery system. As long as three aircraft carriers and can travel up to 10,000mph. Anti-gravity propulsion. Fact or fiction?
I call creative hoax
Quote from: McColm
11)
British Airways sometimes turn over the engines of Concorde kept at Heathrow Airport. Could the SR-71 Blackbird ever fly again?
If the spare parts are available for both the Blackbird and the tankers; most (if not all) of the -135Qs were converted to R/RT standard. And if the government decided to have a member of Big Oil start producing JP-7 again. Of course, in this era of drones, highly unlikely.
Quote
12)
I've seen photos of 'time travel/travelers', if you could travel back in time . What year would you choose and why?
Hang out Rome between 60 and 44 BC, to record the speeches of the great orator Cicero, retrieve copies of Caesar's first publishing of
Commentaries, and to see the downfall of the Republic. Of course, if its not a fixed point in time, meddle to see a future world where Caesar wasn't assassinated.
10) Fiction. The word 'anti-gravity' is enough to decide that.
Quote from: Hobbes on December 25, 2014, 08:01:55 AM
10) Fiction. The word 'anti-gravity' is enough to decide that.
If they solved the gravity problem, a lot of things become possible. Like how to get into space way easier than how they're doing it now
Quote from: McColm on December 24, 2014, 01:34:06 PM
Question 10)
The Sky Dreadnought as seen on TV over parts of Russia. Built by the Americans as the world's deadliest weapon delivery system. As long as three aircraft carriers and can travel up to 10,000mph. Anti-gravity propulsion.
What utter garbage. Who believes that kind of stuff?
Quote from: pyro-manic on December 25, 2014, 01:34:19 PM
Quote from: McColm on December 24, 2014, 01:34:06 PM
Question 10)
The Sky Dreadnought as seen on TV over parts of Russia. Built by the Americans as the world's deadliest weapon delivery system. As long as three aircraft carriers and can travel up to 10,000mph. Anti-gravity propulsion.
What utter garbage. Who believes that kind of stuff?
McColm comes to mind --- ;D
Check it out on YouTube and make up your own mind?
Ten thousand miles per hour. Just a ridiculous number. The current air speed record for a manned aircraft (SR-71 Blackbird) is 2,193 mph. The only things faster are tiny, unmanned and very experimental (see X-41, X-51, HTV-2 etc) or spacecraft (ie out of the atmosphere). The biggest aircraft ever flown was the Hindenburg, which was 245m long, and could do about 80mph. Something three times the size, doing five times the existing record? Not remotely credible. A bit of rubbish footage and hours of conspiracy-loony spouting on Youtube is not very persuasive....
Quote from: pyro-manic on December 25, 2014, 02:39:15 PM
Ten thousand miles per hour. Just a ridiculous number. The current air speed record for a manned aircraft (SR-71 Blackbird) is 2,193 mph. The only things faster are tiny, unmanned and very experimental (see X-41, X-51, HTV-2 etc) or spacecraft (ie out of the atmosphere). The biggest aircraft ever flown was the Hindenburg, which was 245m long, and could do about 80mph. Something three times the size, doing five times the existing record? Not remotely credible. A bit of rubbish footage and hours of conspiracy-loony spouting on Youtube is not very persuasive....
Ah, but seeing is believin'! The speed records are only those that the "man" admits to! What do we know about Alien technology and it's input into our own development? I give you as evidence, Stargate SG-1. Everybody thinks it's a science-fiction TV programme for entertainment. I suggest to you that in fact, it is a dramatisation of real events which have occurred in secret, deep in "the black".
Of course, personally, if given a choice between a juicy conspiracy and a monumental cock-up, I'll go for the cock-up, nine times out of ten... ;D ;D ;D
Quote from: pyro-manic on December 25, 2014, 02:39:15 PM
Ten thousand miles per hour. Just a ridiculous number. The current air speed record for a manned aircraft (SR-71 Blackbird) is 2,193 mph. The only things faster are tiny, unmanned and very experimental (see X-41, X-51, HTV-2 etc) or spacecraft (ie out of the atmosphere). The biggest aircraft ever flown was the Hindenburg, which was 245m long, and could do about 80mph. Something three times the size, doing five times the existing record? Not remotely credible. A bit of rubbish footage and hours of conspiracy-loony spouting on Youtube is not very persuasive....
Actually the speed record for a manned, powered aircraft is 4,520 mph for the X-15. The SR-71 record is for an aircraft that takes off under it's own power.
But that's what the Loominarty want you to think! They've been conspiring with the Vogons for centuries, to demolish the Earth so they can build a new hypersace bypass. The whole Stargate thing is an elaborate deception......
Quote from: Weaver on December 25, 2014, 05:30:47 PM
Actually the speed record for a manned, powered aircraft is 4,520 mph for the X-15. The SR-71 record is for an aircraft that takes off under it's own power.
I stand corrected. Though the X-15 is even smaller than the Blackbird, and as you say can't take off on its own...
12) I've thought about this. December 8th 1988. Portsmouth. UK. I'd find my 21 year old self, hand him a packet of condoms and tell him using them would save him a lot of trouble.
Quote from: McColm on November 08, 2014, 11:04:59 AM
Thanks,
Question 2)
Has there ever been a gas turbine engine fitted to an aircraft?
This one has been well covered,
Perhaps a better question would be "has there ever been a steam turbine fitted to an aircraft".
The answer to which is almost certainly no.
However, Junkers had a project for a 3000hp steam turbine which was cancelled around 1940/41, while two steam projects were started later in WW2 for powering the Me 264. One was to be rated at 4000hp and the other at 6000hp.
The plan was to use a mixture of liquid fuel and pulverised coal to fire the boilers, at least until the liquid fuel situation improved.
Components for the 6000hp version were under construction at the end of the war, so the unit hadn't been tested.
There were 4 boilers per turbine, IIRC.
Another question would be "has any aircraft been powered by a steam engine".
The answer to this is yes:
https://www.youtube.com/watch?v=nw6NFmcnW-8
Quote from: rickshaw on December 25, 2014, 02:18:37 AM
12. 1066 to witness the Battle of Hastings and solve, once and for all what happened to Harold. Was it an Arrow in the eye or did he survive the battle and was hunted down?
Probably cut down in the final scrimmage and then trampled before being dismembered....probably.
My 12. ? Far to many that I'd want to observe to see if the perceived version of history is correct and I'd also be scared stiff of the consequences of any action of mine that changed the course of history :blink: Mind you the Trouser Legs of time theory could be correct ? :rolleyes:
My personal 12 would be to get a certain lady to go and see "Blazing Saddles", would have been interesting to see how things would have turned out and that's all I'm saying ;)
Quote from: McColm on December 25, 2014, 01:57:57 PM
Check it out on YouTube and make up your own mind?
Erm! think about it dude!, don't you think (just for a minute) if the US had anything remotely capable of that, do you reckon they'd spend billions of dollars on a massive launch system that they have just tested to shoot a tiny capsule to Mars --- and also if they did, do you really think they'd take it and put it on show in the Ukraine ---
Just saw an article on YouTube and thought "that's a wind-up", has to be or is it?
There's a lot of unexplained stuff out there, with your expertise and experience. The lay person like me, needs to know, the how or why that works.
Quote from: McColm on November 08, 2014, 08:09:39 AMThe Armstrong Whitworth Apollo was fitted with Mamba engines, in an early photo four-bladed propellors are on the inner engines and three-blades on the outer. Would this improve performance, if fitted on another four engined aircraft?
Do you mean the engine, the prop arrangement or both?
Quote from: McColm on December 26, 2014, 11:00:35 AM
Just saw an article on YouTube and thought "that's a wind-up", has to be or is it?
There's a lot of unexplained stuff out there, with your expertise and experience. The lay person like me, needs to know, the how or why that works.
Something else that just came to mind, the dash-cam video photo-shop was done in the Ukraine/Russia, it wouldn't surprise me that someone in the Putin regime is just trying to wind up their own people there ----
Quote from: KJ_Lesnick on December 26, 2014, 11:34:10 AM
Quote from: McColm on November 08, 2014, 08:09:39 AMThe Armstrong Whitworth Apollo was fitted with Mamba engines, in an early photo four-bladed propellors are on the inner engines and three-blades on the outer. Would this improve performance, if fitted on another four engined aircraft?
Do you mean the engine, the prop arrangement or both?
Both
Quote from: McColmBoth
1. What aircraft would you want to be fitting the engine to?
2. Regarding the prop, are we talking a plane with a three bladed prop, a four-bladed prop or what?
As I said before, I came across the A.W. Apolo which was fitted with both 3 and four propellers. As no other aircraft has been fitted out this way, I can assume that there's no advantage gained in performance or endurance otherwise there would be more than one example listed.
Yes there was.
Consolidated Coronados were fitted with 4 bladers on the inboard engines and 3 bladers on the outboards after they found some resonance problems in the fuselage when using 3 bladers on all four engines.
(https://www.whatifmodellers.com/proxy.php?request=http%3A%2F%2Fimg538.imageshack.us%2Fimg538%2F4470%2FN2NwnY.jpg&hash=38a2c636a135ad372059785749e700784324f69c)
Quote from: PR19_Kit on December 28, 2014, 03:09:28 AM
Yes there was.
Consolidated Coronados were fitted with 4 bladers on the inboard engines and 3 bladers on the outboards after they found some resonance problems in the fuselage when using 3 bladers on all four engines.
(https://www.whatifmodellers.com/proxy.php?request=http%3A%2F%2Fimg538.imageshack.us%2Fimg538%2F4470%2FN2NwnY.jpg&hash=38a2c636a135ad372059785749e700784324f69c)
I believe that the same kind of problem was found with some versions of Halifax, but I could be getting mixed up as I am writing this off the top of my head.
Gondor
Thanks Kit, :bow:
Question 13)
Convair had the trademark twin tail fins on most of their aircraft in the flying prototype stage changing over to the single vertical tail fin on such models as the PB4Y Privateer, B-36 and XC-99.
Is there a big difference in stability between a single and twin or multiple tail fins?
I know deck space on an aircraft carrier or the height of the hanger roof does play a part in the selection but I'm not too sure why Convair changed designs?
Quote from: McColm on January 02, 2015, 08:31:24 PM
Question 13)
Convair had the trademark twin tail fins on most of their aircraft in the flying prototype stage changing over to the single vertical tail fin on such models as the PB4Y Privateer, B-36 and XC-99.
Is there a big difference in stability between a single and twin or multiple tail fins?
I know deck space on an aircraft carrier or the height of the hanger roof does play a part in the selection but I'm not too sure why Convair changed designs?
The PB4Y was the interesting one, being based on the twin fin B-24.
The initial drawings of the B-36 and XC-99 showed twin fins, while the initial B-36 win dtunnel models had twin fins. It may have been because of stability issues that it was changed.
Or strength and weight?
I can't help but think that a couple of fins perched on the ends of the tailplane would need extra strengthening of the tailplane to react the yaw loads. If there's only one fin on the centreline the taillplane only has to react to its own self-generated pitch loads and can be lighter as a result.
Quote from: PR19_Kit on January 02, 2015, 10:57:05 PM
Or strength and weight?
I can't help but think that a couple of fins perched on the ends of the tailplane would need extra strengthening of the tailplane to react the yaw loads. If there's only one fin on the centreline the taillplane only has to react to its own self-generated pitch loads and can be lighter as a result.
Excellent point.
Just found this in
Magnesium Overcast by Dennis R. Jenkins:
QuoteWhen the Model 36 mockup had been approved in September 1942, it used vertical stabilizers mounted on the ends of each horizontal stabilizer, much like the B-24. There were initial concerns that the vertical stabilizers could shear of during a heavy landing or under severe flight conditions - continued evaluation led to the twin tail being deleted in favour of a single 47-foot high vertical stabilizer. This change would decrease structural weight by 3,850 pounds, provide additional directional stability, and lower the base drag.