They go up, tiddly, up, up.
Those magnificent men in their flying phallic symbols.
An Alabama firm building a 235-foot airship says that the mighty craft will soon make its maiden flight from Moffett Field, the former US Navy dirigible base located at NASA's Ames campus in California. The "Bullet™ Class 580", interestingly, uses a key technology employed by America's flying aircraft carrier airships of the …
1) capture the methane from the cattle in the shed. The stuff just ascends (I think) so if the sheda are airtight above door level, that shouldn't be too hard, and fuelling would be a breeze (sorry)
2) use it as part of the lifting gas in say one small bladder within the main lifting body
3) take methane from that bladder as fuel, which then means as they burn fuel, they also use the lifting gas so the need to vent other lifting gases is eliminated or, at least, reduced.
If they have a collection "bladder" on the roof of cattlesheds across america to catch all those ascending cow farts, that's even greener and stops that nasty ozone depletion and the farmers can be supporting NASA. Not quite "pigs in space" but a start!
Yes, I know the figures dont really add up, but the idea is nice.
Blauhas has the same density as air, so burning blaugas and replacing it with air does not change the buoyancy of your airship. http://en.wikipedia.org/wiki/Blaugas
Condensing the exhaust gas has some good theory behind it. Hydrocarbon fuels have a little over two hydrogen atoms per carbon atom. The carbon dioxide gets thrown away, but for each carbon atom lost you get at least one water molecule - which comes with a free oxygen atom. Oxygen weighs a little more than a carbon, so even if the condensation process looses some water, you still get enough ballast.
A correction and some information: The Akron was not based out of Moffet Field. She was based out of Lakehurst, N.J. The zepellin shed there is still in use. She crashed off the NJ coast in a storm, and Admiral Moffet died in the crash. The Sunnyvale field was renamed in his memory.
The launching of aircraft from the ships only caused the ships to rise about 100 feet. Some very fine calculations there on the designers part. As a side note, the fighters / scout planes had no wheels (removed in an effort to save weight) So when you took off, you better get back to the zep. The only ones that had wheels were the ones that they used to train the new aviators to hook up to the trapeze.
Slap a couple of Predators on this beast, and think of the time the Predators could be real near a battlefield. Interesting concept.
I've always been puzzled by the need to vent the helium. Perhaps someone more knowledgeable can enlighten me.
The helium creates lift by displacing heavier air. If you need to reduce lift, you decrease the amount of air being displaced. So, why not just compress the extra helium into storage cylinders? The weight would remain the same, but lift would be reduced due to less air being displaced. You wouldn't be wasting any by venting, and should you suddenly need more lift for any reason, you just re-inflate the bladder.
What am I missing here? This seems like a pretty simple (too simple?) solution to the need to maintain neutral buoyancy.
but I just did a little maths and I think the issue may be the pressures needed.
A typical divers tank will be pressurised to around 300 bars (~3270psi), so a 3ltr tank could hold 900ltr's of gas at 1 bar. The only problem I see is that those tanks are quite heavy.
Just looked some weights:
Helium = 0.1785 g/ltr
Nitrogen = 1.2506 g/ltr (~70% of atmosphere)
So 1 ltr provides just over 1gram of lift.
900 ltr ~= 964g lift, but a 3ltr divers tank weighs a lot more than 1Kg.
To make this work the pressure vessels would have to use incredible pressures and these would likely be as dangerous as using hydrgen.
El Reg sez:
"According to an announcement issued this week by E-Green Technologies, the Bullet has now undergone a second successful inflation inside a colossal shed in Alabama normally used for agricultural shows (capable of holding up to 1500 cattle)."
Wow, 1500 cattle. Sounds like a lot. What does that translate to in Bulgarian Airbags?
If you want to see how the US Dept of Defense is investing the 517 million for the LEMV program for the US Army, try: www.hybridairship.net which has a list of press links and information on hybrid air vehicles and older airship designs like this E green thing. I hope it does not bump into the Zeppelin at Moffet field.