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The more I read about NERVA, the more I'm  The main engine design put out 250k lbs of thrust. Thats comparable to the Atlas F boosters which put out 300k lbs thrust. Jesus.
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Nov 28, 2015 02:00
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benito posted:In one way, yes... Suddenly thats a baddas loving medal i would wear with pride if i was still alive.
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Nov 28, 2015 02:12
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Nebakenezzer posted:A better photo of the Dynairship, with 747 and C-5 for scale. These were uploaded by the designer himself, who has a deviantart page. This is a later project he worked on. It was nuclear powered! That's some Gernsback Continuum stuff right there. Nebakenezzer posted:There's also the Aerolift Cyclo-Crane And I remember seeing that video on TV when it happened. I had forgotten about it till your post. Thanks for the reminder.
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Nov 28, 2015 03:32
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You missed the best one:  Yes, that is the 'The' Gadget. The nuclear device tested at Alamogordo during the Manhattan project.
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Nov 28, 2015 03:39
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Yes, but here's zero detail on the physics package, as opposed to the wiki page which draws heavily on John Coster-Mullen's work.
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Nov 28, 2015 06:05
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Koesj posted:Yes, but here's zero detail on the physics package, as opposed to the wiki page which draws heavily on John Coster-Mullen's work. No no, I mean it's really well done. And yeah, I know you can find physics package designs pretty readily.
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Nov 28, 2015 06:07
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Oh yeah sure, I freaking love aerospace projects review anyway, shame it costs money that I don't want to spend on such obscure stuff.
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Nov 28, 2015 06:13
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It's the future already e: I know the X47 and friends have been around forever now, but this photo (a nEUROn) just looks like it shouldn't have been taken for another 50 years Captain Postal fucked around with this message at 03:20 on Nov 29, 2015 |
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Nov 29, 2015 03:18
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Captain Postal posted:It's the future already Next Ace Combat looking good...
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Nov 29, 2015 04:44
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Captain Postal posted:It's the future already  As I suspected, a bucket hat. E-  Yup, bucket hat Finger Prince fucked around with this message at 14:49 on Nov 29, 2015 |
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Nov 29, 2015 04:58
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YF19pilot posted:Next Ace Combat looking good... Wasn't there an Ace Combat game where you were secretly a UCAV?
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Nov 29, 2015 05:10
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wdarkk posted:Wasn't there an Ace Combat game where you were secretly a UCAV? Maybe AC3, which I haven't played and many feel was the best in the series.
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Nov 29, 2015 05:13
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Ace Combat 3 was really different from 2 and 4, in some ways weird as gently caress and others very good. It apparently had a different release in Japan which had more content.
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Nov 29, 2015 06:32
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Cliff diving: https://www.youtube.com/watch?v=5DDxm7GajKw From the cockpit: https://www.youtube.com/watch?v=F_8NMODxSlM
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Nov 29, 2015 09:44
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ehnus posted:Cliff diving: https://www.youtube.com/watch?v=5DDxm7GajKw
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Nov 29, 2015 10:15
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loving hell, was was hoping to post some Alaskan aviation goodness on page 907, but goddamn, there is no way I can beat that.
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Nov 29, 2015 10:41
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Mazz posted:Ace Combat 3 was really different from 2 and 4, in some ways weird as gently caress and others very good. It apparently had a different release in Japan which had more content. From the cutting room floor wiki: "The original version comes in two discs, it has 52 missions, story branches, multiple endings, and more. The western version only has one disc with 36 missions, the story is linear with only one ending, a lot of the anime cutscenes are gone, unique characters were replaced with generic stand-ins, and more." Pretty sure no one knows why they did that other than Namco.
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Nov 29, 2015 11:19
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ehnus posted:Cliff diving: https://www.youtube.com/watch?v=5DDxm7GajKw I don't think anything I ever do will come close to being as cool as this.
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Nov 29, 2015 13:52
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Dannywilson posted:loving hell, was was hoping to post some Alaskan aviation goodness on page 907, but goddamn, there is no way I can beat that. Your only chance of topping him would be to post clips from the Big Rocks & Long Props videos. https://www.youtube.com/watch?v=AUP8oD6u708
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Nov 29, 2015 20:50
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 LockMart's airship has been certified by the FAA, on sale in 2018
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Nov 29, 2015 21:13
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The F-35 of LTA craft is a go!
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Nov 29, 2015 21:16
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Now they just need to extort several billion dollars to design a "VTOL version" for the USMC.
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Nov 29, 2015 21:26
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If they sell the USMC a Akron/Macon version would that be the navy's army's airforce's airforce?
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Nov 29, 2015 21:31
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I wonder how much of the cost is the helium.
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Nov 29, 2015 21:51
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It'll fly in 2020 but won't carry any cargo until 2024. It will also (somehow) break the necks of everyone nearby.
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Nov 29, 2015 21:57
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Supposedly it can be scaled up to carry 500 tons of cargo (from the 20t this is). I would love to see that deplete world helium reserves
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Nov 29, 2015 22:07
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Sagebrush posted:I wonder how much of the cost is the helium. Quick snooping around doesn't give a displacement figure, it seems the size has not been released. Cat Mattress posted:Now they just need to extort several billion dollars to design a "VTOL version" for the USMC. I know this is a joke, but apparently with an unspecified 'reduced load' it can take off in 150m. 20% of its lift is dynamic. At a full load, it needs 750m to take off, but bear in mind this 750 m can be literally anything - sand, ice, bog, open water, etc. The things on the bottom are hoverskirts so it can move around on the ground. Lockheed (so take this as you will) says that in terms of moving stuff around, the costs of the airship are a tenth that of a helicopter. slidebite posted:Supposedly it can be scaled up to carry 500 tons of cargo (from the 20t this is). I would love to see that deplete world helium reserves Seriously. The 500 ton version would be 800+ ft long. As for the cost of helium for it, well, the Hindenburg was 800 ft, and displaced 200,000 cubic meters, or 7,000,000 square feet if you prefer. I'd love to get a price on this, but while lots of articles discuss the price of helium, ah, rising, I can't find a modern price quote. Incidentally, on that same chapter from the big book of airships, they discuss the work of two aeronautical profs defending hydrogen in airships as vastly more efficient. They've also designed a "double envelope" where a layer of helium encloses a second cell of hydrogen. They say such a development is necessary due to cost and hydrogen's greater efficiency as a lifting gas. (I know chemically the difference is not much, but somehow these guys get a real world efficiency bonus of 50% with Hydrogen as opposed to helium. I have to go out, but if you want more hot air about this let me know and I'll dig it out.
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Nov 29, 2015 23:03
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I found a recent article about Praxair buying 275 million cubic feet of helium at auction for about $28 million, so 10 cents a cubic foot in bulk seems fair. http://www.blm.gov/nm/st/en/info/news_releases0/2015/august/fy16_helium_sale_and0.html The Hindenburg-sized model would only cost $700,000 to fill -- really not that much, considering. Hydrogen is well under 1 cent per cubic foot when manufactured through natural gas cracking, though. Sagebrush fucked around with this message at 23:16 on Nov 29, 2015 |
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Nov 29, 2015 23:12
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FY2014 Bulk helium from the federal helium reserve was $2.49/m³ to governmental users, $3.43/m³ to anyone else. Private industry price estimated at $7.21/m³ for grade A helium. Source
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Nov 29, 2015 23:16
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Nebakenezzer posted:(I know chemically the difference is not much, but somehow these guys get a real world efficiency bonus of 50% with Hydrogen as opposed to helium. I have to go out, but if you want more hot air about this let me know and I'll dig it out. He has an atomic mass of ~4, H2 is ~2. So 22.47 L of He @ STP weighs ~4 grams, while 22.47L of H2 @ STP weighs ~2 grams. I don't know the mass of the lifting gas of an airship vs the empty mass, but quick and dirty approximation, if the He mass is 50%, structure is 40% and payload is 10%, swapping to H2 gives ~25% lifting gas, 40% structure and ~35% payload, more than triple. Subtract from payload the mass of the second envelope and reserve hydrogen and you would still probably be better off. Although as I understand it, there is no envelope material in existence that could hold H2 for an extended period of time as the molecules are so small, so it may add endurance limits and the requirement to devote payload capacity to bottles of gas to recharge. I'm half-remembering but possibly-imagining that this is the biggest issue with Hydrogen now days. edit: comedy option - dissociate h2 from atmospheric methane/ammonia/etc in flight and keep going indefinitely, or until you go WHOOOMP Captain Postal fucked around with this message at 00:05 on Nov 30, 2015 |
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Nov 29, 2015 23:58
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Sagebrush posted:The Hindenburg-sized model ... can't wait to see this inevitible bad ending to this
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Nov 30, 2015 00:11
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There was only one Hindenburg disaster. Do we let one plane crash stop us from flying airliners? No. Get back on the horse, I say.
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Nov 30, 2015 00:14
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There sure were a lot of other airship disasters though https://en.m.wikipedia.org/wiki/List_of_airship_accidents Yes I know the early days of fixed wing aircraft had their share too, but even back then there were far more of them around
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Nov 30, 2015 01:13
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Captain Postal posted:He has an atomic mass of ~4, H2 is ~2. So 22.47 L of He @ STP weighs ~4 grams, while 22.47L of H2 @ STP weighs ~2 grams. This is not how chemistry works, but it's really close in this case. Helium has a density of 0.1786 kg/m3. Hydrogen has a density of 0.08988 kg/m3. Air has a density of 1.2754 kg/m3. If you have 2e5m3 displacement, then you have ~250,000kg of air, 36,000kg of helium, or 18,000kg of hydrogen. So your helium ship has 215 tonnes of lift, while your hydrogen ship has 232 tonnes. Subtract out the weight of everything that makes the ship, and that's your available net lift. Note that hydrogen and helium are your only viable lifting gases. Methane is about .6-.7kg/m3, neon is .9 or so, oxygen and nitrogen are in the 1.25kg/m3 (so about the same as air). If you had a structure that could displace that same 200,000m3, yet could hold a hard vacuum, then you'd get even MORE buoyancy than hydrogen! You'd have all 250 tonnes of lift available! If you could make the whole thing weigh less than 18,000kg, you'd beat out hydrogen as a viable lifting medium.
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Nov 30, 2015 01:22
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Use hydrogen but for military reasons tell everyone you are using helium. Even label the bottles He. Get rumbled when a pair of marines die from trying to make their voices go squeaky. for the fun police: yes, I know using straight He in the same manner will kill you too
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Nov 30, 2015 01:28
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What would be the physical effects of 200,000m3 of vacuum failing its containment?
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Nov 30, 2015 01:32
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Helium is rare and hydrogen is dangerous. So obviously what we need is rigid, pressure-resistant envelopes so that the airship can be buoyed by pure vacuum.
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Nov 30, 2015 01:35
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joat mon posted:What would be the physical effects of 200,000m3 of vacuum failing its containment? If the whole containment failed catastrophically and uniformly (the whole thing just implodes) then it's literally the loudest sound possible to be generated in the atmosphere. Since sound waves are formed by rarefaction, then the loudest possible sound has a vacuum in its trough. You now have a single sound wave with a trough the width of your containment vessel at the maximum possible differential pressure, and therefore the maximum possible energy transmittable in air. tl;dr: It would be very loud.
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Nov 30, 2015 01:38
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Cat Mattress posted:Helium is rare and hydrogen is dangerous. So obviously what we need is rigid, pressure-resistant envelopes so that the airship can be buoyed by pure vacuum. This, but once we find a suitable material, forget the airship and make a space elevator instead.
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Nov 30, 2015 01:38
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Cat Mattress posted:Helium is rare and hydrogen is dangerous. So obviously what we need is rigid, pressure-resistant envelopes so that the airship can be buoyed by pure vacuum. They tried during the 19th century; the method was thin-walled hollow copper spheres, fully evacuated. Turns out that the strength needed, whether by internal bracing or thicker walls, makes them heavier than air so the whole thing fails. Be interesting to see if it's even theoretically possible with whatever unobtanium.
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Nov 30, 2015 01:39
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