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Modular Airships
Making Airships Modular to improve cost and bring affordable personal flight | |
I posted about constructing my own Personal LTA Flying Machine a while back on Brassgoggles, and someone there mentioned cluster ballooning as being a lot cheaper. That has got me thinking: why not combine the two, making lift modules which can be joined together to produce the lifting envelope? So your
Airship would be sort of like a cluster balloon, except cheaper and steerable. Such common modules could also be configured for lifting a small house, for example. Basically, it's OTRAG (see link) for Airships. If one module pops, you'll descend to the gound slowly, instead of crashing.
If the modules are cylinders 4m long and 1m diameter, and filled with Hydrogen, they should have a lift (accounting for the weight of the material) of 12.5kg each, if the material weighs 100g/m^3 (achievable with plastics).
Thoughts? If they can be mass produced... Airships for everyone.
EDIT: I made a mistake working out the surface area. Actual lift would be around 11kg instead of 12.5. Still...
The point of making it modular is to both improve safety and reduce cost, since the same basic cheap (since all they are are plastic cylinders, possible to manufacture in a factory quite easily, with connecters attached) components can be used to produce different airships, and if one goes, one goes, and the airship merely sinks down. They don't need plumbing, except on a few control modules for ascent/descent. I'm not sure about solar heating, but it should be (hopefully!) possible to use overpressurization. Blimps use it, after all. Making it a cylinder makes connecting them easier while still retaining some of the advantages of a sphere. I envisoned a keel on the underside of each module, that could be connected together to link the modules.
OTRAG
http://www.astronautix.com/lvs/otrag.htm
Astronautix article for OTRAG [Selky, Aug 17 2009]
brassgoggles.co.uk: author's similar post
http://brassgoggles.../topic,17937.0.html
Not quite sure where you want comments, here or there? [jutta, Aug 17 2009]
brassgoggles.co.uk: cluster ballooning thread
http://brassgoggles...x.php?topic=16186.0
19th century space pilot = author [jutta, Aug 17 2009]
H2/He Airship
Solar_2f_20Fuel_20C...20H2_2fHe_20Airship
Uses bouyant fuel (unpressurised hydrogen) [BunsenHoneydew, Aug 22 2009]
[link]
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A good personal airship should seek to minimize both gas envelope weight/volume and air drag. Minimizing envelope weight will minimize gas volume needed thus lowering price. Minimizing air drag will lower propulsion requirements which will lower weight and ultimately lift gas costs. The best shape to minimize envelope weight is the sphere. The best shape to minimize air drag is the teardrop. Multiple parallel cylinders would carry more envelope weight and have more air drag than multiple inline spheres. Also you need to account for solar gas heating which will either require envelopes that can handle the pressure, expand to equalize the pressure or some kind of plumbing to vent/pump away the excess gas. Stacked cylinders would make plumbing challenging. You could build it into the design but that would remove the safety advantages of the multiple envelopes.
So if you switch to multiple inline or nearly inline spheres, I will bun. |
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well, you've got your rigid dirigibles: they contain baggies of lift-gas and are quite aerodynamic all things considered. |
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For what you've envisioned you'd want each module to be hexagonal in cross-section and have attachment hardware to rigidly attach the sides to adjacent modules to reduce chafing, and cabling or structuring that goes through the modules, either lengthwise if your modules are going to all point up for a cluster-balloon, or widthwise if they're going to point horizontally for a cluster airship; all to spread the payload's weight amongst the modules. A keel would also be adviseable. [edited out a bit of bad science about load distribution] |
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In essence what you would be building would be a dirigible minus the skin and framing. |
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My own airship (long since been abandoned in favour of the Hullaballoon, but it's still in the garage) consists of a rigid'ish deck around which are symetrically placed 6 of your (well mine, actually: they're bigger) modules. |
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(whaddaya know, somebody else reads Brass Goggles) |
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The point of making it modular is to both improve safety and reduce cost, since the same basic cheap (since all they are are plastic cylinders, possible to manufacture in a factory quite easily, with connecters attached) components can be used to produce different airships, and if one goes, one goes, and the airship merely sinks down. They don't need plumbing, except on a few control modules for ascent/descent. I'm not sure about solar heating, but it should be (hopefully!) possible to use overpressurization. Blimps use it, after all. Making it a cylinder makes connecting them easier while still retaining some of the advantages of a sphere. I envisoned a keel on the underside of each module, that could be connected together to link the modules. |
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What you're proposing is a more efficient cluster-balloon module... go for it. [+] but be advised adding to safety makes for less spectacular fireworks possibilities. |
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Bah. Hydrogen on it's own doesn't give very good fireworks possibilities anyway, since it burns clearly. Coating it in rocket fuel, like the germans did with Hindenburg, would though... |
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In response to Jutta - both here and there :) |
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Thoughts? I have thoughts. |
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Rather than long thin horizontal sausages, make large, flat disk shaped compartments (also known as short, wide cylinders), hanging vertically like a coin balanced on edge. The disks are 20 feet thick, and large (bouyant) enough to lift a fully laden standard 20 foot shipping container. Two will lift a 40 footer, and so forth. |
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Tow them into position with ground based tugs and stack your disks horizontally, like a pancake stack on its side. The containers then become a conga line/train. |
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Add a bouyant nose cone, supporting a pilot compartment, and a tail section with engines, fuel and control surfaces, and viola, containerised blimp freight system. |
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Build in a safety factor of say 1:10, such that in the event of a punctured envelope, the remaining 9 compartments in a 10-container train can support the rest by dumping ballast. |
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Also see [linky] for fuel:weight savings |
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My idea was designed for small airships, up to 200kg with 4m long 2m dimeter modules, 1 tonne with 6m long 3m diameter modules, and 10 tonnes with 8m long and m dimaeter modules (yes, I'm aware that that means 100 modules). |
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Come to think of it, two 8m long 4m diameter modules on there own would make a nice personal Airship... |
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Ah, I see Mr. Atterton at brassgoggles has had the same thought as me. |
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//would be sort of like a cluster balloon, except cheaper// i like the idea, but how did you envision the price to be below that of a vehicle composed entirely out of 10-a-dime modules (aka balloons)? |
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You can get weather balloons 10 for a dime? |
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Reusability, and the capability to arrange it in a more aerodynamic shape. |
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ah, my bad; I read cluster balloons and envisioned a cluster of balloons - didn't know it had to be weather balloons. I guess the wheather balloons are preferrable to normal balloons because of the better surface/volume ratio? |
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