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Wibbleman posted:... The ME163 had wings for lift and a rocket for thrust, and worked pretty well for its design envelope. Flying for 15 minutes then crashing?
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# ? Jun 29, 2010 23:38 |
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# ? May 21, 2024 16:33 |
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MrChips posted:I know it's an abbreviation. And if you can show me an abstract or a paper that refers to this engine as a "SCRamjet" instead of "scramjet", then I'll believe you. Jesus christ you pedantic, intolerable weenies. Look at what you're arguing about. LOOK. Shut up and post hot radial engines. Whoops!
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# ? Jun 29, 2010 23:45 |
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MrChips posted:The scramjet is pretty much the most likely ticket to affordable, reliable transportation to orbit, especially if researchers can iron out the kinks with regard to burning conventional hydrocarbon fuels. So if I'm understanding correctly, there are two options for building a SSTO lifter: 1) Use a rocket but lug your oxidizer around with you. This has the advantage of simplicity and atmosphere/speed independence, but taking oxidizer requires a heavier fuselage to carry more weight, which in turn requires more fuel, leading quickly to larger scale craft and increased fuel requirements for a given payload. 2) Use a turbine/ram/scramjet hybrid to burn air to attain orbital speed in the atmosphere. This has the advantage of being relatively efficient for a given payload mass, since a higher ratio of the lifter's loaded weight is used for payload (versus fuel). The drawbacks include the need for a separate thrust system in order to function without atmospheric oxygen and the obvious (significant) engineering hurdles involved in building a craft powered by four separate paradigms of propulsion which must survive mach 25+ speeds within the atmosphere. Sound about right? ^^^ Fine, how about some UGLY radial engines in charming but ugly helicopters: Even though it's a funny place to stick a radial engine in a heli, I suppose Sikorsky had his reasons for using a 1931-vintage engine for his otherwise modern chopper... Sterndotstern fucked around with this message at 18:13 on Jun 30, 2010 |
# ? Jun 29, 2010 23:46 |
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Sterndotstern posted:
I understand now. http://www.flickr.com/photos/bonzoesc/2220032567/in/set-72157603795819604/
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# ? Jun 30, 2010 02:12 |
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Sterndotstern posted:
Sikorsky used radial engines into the early 1950's due to the simple fact that turboshaft engines capable of powering a helicopter hadn't been developed yet. Turboshafts were first developed in the late 1940's, but it wasn't until the mid 1950's that they were refined to the point of making the large radial engines obsolete.
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# ? Jun 30, 2010 02:32 |
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Something that hasn't been mentioned yet. The oxidizer weighs something like four times as much as your fuel does. So ditching the oxidizer doesn't just save you "half the weight" it saves you 4/5 of the weight! That has massive effects on structure.
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# ? Jun 30, 2010 02:58 |
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More stuff...
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# ? Jun 30, 2010 03:15 |
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God that ME-262 is so loving sexy.
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# ? Jun 30, 2010 03:20 |
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Yeah it is.
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# ? Jun 30, 2010 03:26 |
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LOO posted:Yeah it is. I'm sure you guys already knew all about this - but some guys have been building replicas up in Washington, and they are GORGEOUS. http://www.stormbirds.com/project/index.html
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# ? Jun 30, 2010 04:46 |
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Nerobro posted:Something that hasn't been mentioned yet. The oxidizer weighs something like four times as much as your fuel does. So ditching the oxidizer doesn't just save you "half the weight" it saves you 4/5 of the weight! That has massive effects on structure. Ah, perspective, thanks. I looked up the shuttle tank -- 4/5 of it is hydrogen tank, only the nose piece is oxygen, but the oxygen weighs 6 times as much. So the real trick for scramjets is fueling? Currently they use hydrogen, which is hard to package, so what are the dense alternatives? I imagine trouble with scramjet fuel is the time required to extract energy from combustion. You basically have to use hydrogen fuel because you have less than 1msec of burn time unless you build a really long engine. Even F1 cars have almost 3ms of burn time.
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# ? Jun 30, 2010 05:25 |
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Sterndotstern posted:Ah, perspective, thanks. I looked up the shuttle tank -- 4/5 of it is hydrogen tank, only the nose piece is oxygen, but the oxygen weighs 6 times as much. I wonder what crazy CG fuckery was going on when they decided to put the oxygen at the top of the fuel tank? I've always figured (never actually looked it up) that the shuttle must have some wacky CG and mass distribution going on. The midsection is almost completely empty cargo bay (on landing, anyway), which a bunch of mass at the back from 5 engines (the three mains and the two OMS), and all the life-support/creature comforts/squishy humans up front. Must have a pretty huge moment of inertia compared to aircraft that are in the same size/weight range with all that weight as far forward and back as it can get. Where is the fuel for the OMS engines stored? quote:So the real trick for scramjets is fueling? Currently they use hydrogen, which is hard to package, so what are the dense alternatives? Well, Kerosene is already used as rocket fuel (RP-1) and jet fuel. The mass ratio between kerosene and oxidizer is way lower than it is for hydrogen/oxygen (3.5 compared to 8 at the stoichiometric ratio), which is probably the main reason it's used in rockets. Don't know how it is about burn speed, that's not really my area.
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# ? Jun 30, 2010 06:50 |
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ApathyGifted posted:Well, Kerosene is already used as rocket fuel (RP-1) and jet fuel. The mass ratio between kerosene and oxidizer is way lower than it is for hydrogen/oxygen (3.5 compared to 8 at the stoichiometric ratio), which is probably the main reason it's used in rockets. Don't know how it is about burn speed, that's not really my area. Kerosene is used because it is denser (space efficient), although it is heavier for a given energy quantity. In a first stage, such enormous volumes are necessary that the structure to hold cryogenic hydrogen would be expensive and also would negate much of the weight advantage. That's why the Saturn V used kerosene in the first stage but hydrogen in the upper stages.
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# ? Jun 30, 2010 07:39 |
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Sterndotstern posted:So if I'm understanding correctly, there are two options for building a SSTO lifter: Jesus... I'd really love to see the shaft arrangement in that thing.
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# ? Jun 30, 2010 15:31 |
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sandoz posted:Jesus... I'd really love to see the shaft arrangement in that thing. H-19 (the middle one) Westlan Wessex, a turboshaft powered version of the H-34. (the first and last ones are H-34s)
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# ? Jun 30, 2010 18:22 |
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joat mon posted:
One of my dad's friends used to fly H-34s. Said he would piss the bed at night everytime he even thought about having to put one down in water. Since the pilots sit so loving high and the balance of it making it immediately flip when it touches down in it.
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# ? Jun 30, 2010 18:44 |
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McDonnell Douglas F-4 Phantom II.
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# ? Jul 1, 2010 05:14 |
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LOO posted:McDonnell Douglas F-4 Phantom II. The most beautiful fighter ever.
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# ? Jul 1, 2010 07:27 |
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River Raid posted:One of my dad's friends used to fly H-34s. Said he would piss the bed at night everytime he even thought about having to put one down in water. Since the pilots sit so loving high and the balance of it making it immediately flip when it touches down in it. I'd be more worried about the driveshaft whirling around between me and my copilot.
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# ? Jul 1, 2010 13:09 |
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There are few planes that get me excited like a camo F-4. One of my best (and earliest) Air Force moments was just a couple of days after reporting to my first assignment, Tyndall AFB. US 98 runs right through the middle of the base, separating the flightline from the rest of the base. Tyndall is home to a unit that flies QF-4s (literally remotely piloted F-4 Phantoms) in combat simulations...manned fighters will actually engage and shoot them down so pilots get to actually experience real missile launches and whatnot. The QF-4s are painted grey and orange. But there's one F-4 they bring out for the airshows, and actually use a pilot to fly, and it's in full up camo paint. At the time, Tyndall was also the home of the F-15C schoolhouse, although over the past couple of years that pipeline has been moved to Oregon so the F-15s are gone. Tyndall is also where the F-22 schoolhouse is. So I was at a red light at the gate about to leave the non-flightline side to get on 98, and I see an F-4 take off...the camouflage one. AWESOME! About 15 seconds later a pair of F-15Cs go roaring after it. YES! Then a pair of F-22s. All in the span of one red light.
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# ? Jul 1, 2010 14:45 |
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sandoz posted:Jesus... I'd really love to see the shaft arrangement in that thing. joat mon posted:
I was thinking the exact same thing and I knew AI would pull through for me.
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# ? Jul 1, 2010 15:09 |
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Couple more Phantom shots I like.
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# ? Jul 1, 2010 15:57 |
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sandoz posted:I'd be more worried about the driveshaft whirling around between me and my copilot. I'll have to ask him next time I see him if that was something that bothered him or if he just kept that out of mind. He flew a lot of missions around the Gulf coast and near the North Vietnam border calling artillery in them. So the ocean always being close probably made the fear of a water landing that much more real. He always said he respected the Army for being smarter than the Marines for not deploying those deathtraps in Vietnam. Told me he was thrilled the day he transferred to a UH-1 squadron even if it meant more dangerous missions.
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# ? Jul 1, 2010 18:41 |
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Spent all last weekend at the Great Minnesota Air Show, volunteering for the CAF and taking pictures. Blue Angels sneak pass Blue Angels An EA-6B Prowler (one of the static displays) leaving at the end of the show. The F-22 Raptor We also got a private tour of the Raptor from the team superintendent. Awesome plane! (I'm in the white shirt)
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# ? Jul 1, 2010 20:23 |
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LOO posted:Couple more Phantom shots I like. Awesome pics, thanks for posting them! I used to live a few miles from Gowen Field in Boise, Idaho where these would fly over my house DAILY. They're pretty much the reason I became an aviation nerd. pbpancho posted:blue angels & stuff NurSpec fucked around with this message at 20:28 on Jul 1, 2010 |
# ? Jul 1, 2010 20:24 |
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Have some more Angels Seahawk doing a mock refueling B-17 dropping a deadly payload of... watermelons Not my best, but I liked them when they were taken
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# ? Jul 2, 2010 00:52 |
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ursa_minor posted:I'm sure you guys already knew all about this - but some guys have been building replicas up in Washington, and they are GORGEOUS. Holy poo poo, I had no idea this existed. To make it better I live pretty much right on the approach to Paine Field and more then once have glanced out my window and seen the Dreamlifter. I can't tell if they're currently flying the thing, but I'm going to keep my eyes peeled from now on.
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# ? Jul 2, 2010 04:20 |
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QuiteEasilyDone posted:Have some more Angels These are both fantastic shots and utterly staggering displays of human ability. Nothing impresses the mind like perfect control. Edit: recommend a polarizing filter for your next sunny day
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# ? Jul 2, 2010 05:20 |
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Sterndotstern posted:These are both fantastic shots and utterly staggering displays of human ability. Nothing impresses the mind like perfect control. What makes it even more impressive is that those guys fly without the benefit of a G-suit. Due to the precision required for that kind of flying, Blue Angel pilots fly bracing their right arms on their right thighs, and since G-suits use inflatable bladders on the abdomen and legs, the suit would jostle the stick whenever it inflated. To compensate for the fact that most of the formation maneuvers pull about 4G's (the solo pilots pull close to 7), the pilots have to tense up their abdominal and leg muscles during maneuvers to keep from blacking out. After the team experienced a fatal crash while practicing for a show in 1999 (caused by a pilot blacking out in a high G turn), the Navy considered forcing the team to wear G-suits, but relented after it was determined that the accident pilot was suffering from a rib injury that kept him from tensing up properly during flight.
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# ? Jul 2, 2010 06:56 |
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Sterndotstern posted:On a completely different topic, a while ago I posted that air-burning, air-flying technology reached its logical conclusion in approximately 1965 and stated (somewhat controversially) that we're "done" with aircraft. I never got to ask the obvious follow-up question: Where is the next great unsolved problem for aerospace engineering? Late to th' party but I'd say making LTA craft reliable and durable. I think the technology is already there; it just needs to be applied. Of course it's no secret that I'm a airship fanboy so fake edit: How about aircraft carrier submarines? real edit: images Nebakenezzer fucked around with this message at 07:41 on Jul 2, 2010 |
# ? Jul 2, 2010 07:34 |
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Nebakenezzer posted:Late to th' party but I'd say making LTA craft reliable and durable. I think the technology is already there; it just needs to be applied. One thing I really like about the notion of lighter-than-air first stages launching liquid-fueled rockets is a synergy in their fueling needs. They both basically run on hydrogen and oxygen which can be easily obtained my electrolyzing water down at the surface. I think it's loving retarded to burn coal to electrolyze water when we've already proven that we can make even heavier-than-air craft fly using solar power. Imagine how easy it would be if you didn't have to lose altitude all loving night! Use the excess lifting capacity to lift and electrolyze water to provide fuel for rockets. Edit: poo poo, someone tell me a way to build the hydrogen cells out of salt and we can go get some venture capital from Elon Musk. Nebakenezzer posted:I'll see your B-36 and raise you a B-36 with a B-58 back. http://www.youtube.com/watch?v=Pxrwpur_Op8&feature=related Sterndotstern fucked around with this message at 20:41 on Jul 2, 2010 |
# ? Jul 2, 2010 07:57 |
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BeastOfExmoor posted:Holy poo poo, I had no idea this existed. To make it better I live pretty much right on the approach to Paine Field and more then once have glanced out my window and seen the Dreamlifter. I can't tell if they're currently flying the thing, but I'm going to keep my eyes peeled from now on. quote:During flight testing in November 2006, a Cessna 172 being used for a training flight encountered the 747 LCF's wake turbulence while on approach to Boeing Field. The small aircraft was accidentally inverted and lost 1,000 feet (300 m) of altitude before the instructor pilot was able to regain control at just 150 feet (46 m). From the wiki. I hate it when I get accidentally inverted.
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# ? Jul 2, 2010 11:37 |
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One of the coolest aeronautical feats ever has to be Operation Chastise. Did you like skipping rocks across lakes when you were a kid? Try it from an airplane! Operation Chastise was a mission to destroy several German dams during WW2. It involved the Avro Lancaster and some serious outside-the-box thinking. quote:A much-smaller explosive charge would suffice, if it could be exploded directly against the dam wall below the surface of the water, but the major German reservoir dams were protected by heavy torpedo nets to prevent such an attack. quote:Bombing from an altitude of 60 ft (18 m), at an air speed of 240 mph (390 km/h), and at a pre-selected distance from the target called for expert crews. Intensive night-time and low-altitude flight training began. Did it work? Yes! quote:When I was about 150 miles from the Möhne Dam, I could see the industrial haze over the Ruhr area and what appeared to be a cloud to the east. On flying closer, I saw that what had seemed to be cloud was the sun shining on the floodwaters. With the 4th this weekend, if you haven't skipped bottle rockets or mortars accross a lake, you're missing out! Lay the rockets or mortar tube horizontal on the shore/dock and light em off! Also, shoot the bottle rockets straight down into the water and feel the tiny explosion deep underwater through the dock! Vitamin J fucked around with this message at 17:41 on Jul 2, 2010 |
# ? Jul 2, 2010 17:37 |
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Vitamin J posted:Dambusters! http://www.youtube.com/watch?v=LuIJqF8av6I http://www.youtube.com/watch?v=qKHc-U2FNHk
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# ? Jul 2, 2010 20:35 |
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azflyboy posted:After the team experienced a fatal crash while practicing for a show in 1999 (caused by a pilot blacking out in a high G turn), the Navy considered forcing the team to wear G-suits, but relented after it was determined that the accident pilot was suffering from a rib injury that kept him from tensing up properly during flight. Don't forget the crash in 2007 which was also attributed to GLOC: http://en.wikipedia.org/wiki/2007_Blue_Angels_South_Carolina_crash
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# ? Jul 2, 2010 22:41 |
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More stuff.
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# ? Jul 4, 2010 00:12 |
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Just found this... Just a bit of crosswind.
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# ? Jul 4, 2010 00:55 |
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LOO posted:That's some beautiful camo. Is it real? If so, what's it for? Sterndotstern posted:I'll see your B-36 and raise you a B-36 with a B-58 back.
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# ? Jul 4, 2010 01:33 |
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LOO posted:More stuff. Phantoms make me feel
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# ? Jul 4, 2010 01:42 |
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# ? May 21, 2024 16:33 |
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Nebakenezzer posted:That's some beautiful camo. Is it real? If so, what's it for? The Aggressors (they pretend to be the bad guys in exercises) up in Alaska. The Aggressors at Nellis use similar paint schemes, but different colors. I'll try to dig up some pics. Edit: Click here for the full 1373x915 image. I also love the Aggressor colors. Godholio fucked around with this message at 02:32 on Jul 4, 2010 |
# ? Jul 4, 2010 02:29 |