Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
This would work fine, except in terms of success.

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Jetairship

Flying soccer fields
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Build an airship around a central rigid tube, with jet engines on both ends, using aerospike engines rather than regular jet engines if necessary to provide sufficient oxygenation. A more ambitious undertaking might involve a vertical tube as well.

Zip around like a UFO by engines to provide vector thrust and braking as needed.

theircompetitor, Sep 23 2005

Aerospike Engines http://www.aerospac...erospike/main.shtml
[theircompetitor, Sep 23 2005]

Exactly http://www.cisolar.com/HoverShip.html
[tc] there's an email address here for you. [ConsulFlaminicus, Sep 24 2005]

Flying soccer, indeed http://www.space.co..._of_day_050923.html
[theircompetitor, Sep 25 2005]

Dynalifter http://www.dynalifter.com
[theircompetitor, May 12 2006, last modified May 13 2006]

NASA's "sideways" supersonic plane http://venturebeat....s-supersonic-plane/
[theircompetitor, Sep 03 2012]

Not quite jet airship, but interesting http://www.popsci.c...lider&lnk=2&con=IMG
[theircompetitor, Oct 06 2014]

[link]






       What's an aerospike engine?
moomintroll, Sep 23 2005
  

       I really like this idea, though I have a few concerns:   

       1. Finding a material that is both light enough for this and strong enough. If you build a very aerodynamic shape, it just won't have the volume to float. If you build a round shape, wind resistance will break your ship apart well before you get going very fast.
2. Why?
  

       Ok, forget 2 - it doesn't matter why.   

       Wait, I don't get the vertical tube bit. I imagined this in the shape of a pencil, but with two jet engines attached to the sides.
Worldgineer, Sep 23 2005
  

       [World], so that you would have both vector thrust by combining the vertical lift with the horizontal thrust engines.
theircompetitor, Sep 23 2005
  

       Couldn't you just use 3 engines? They could be used to turn the ship in any direction.
Worldgineer, Sep 23 2005
  

       I was thinking of UFO style movement -- rapid movement in all directions without changes in angle of attack.
theircompetitor, Sep 23 2005
  

       Ok, I think I get it. You don't mean for the tube to be filled with helium/hydrogen - it's a path for the combustion air. Adding another one for up and down, and perhaps a third for left and right. (actually, it might make more sense to have 3 sets of 2 tubes, so you don't have to worry about getting air past an engine)   

       Much different than I'd imagined, but good.
Worldgineer, Sep 23 2005
  

       I thought aerospike engines required like mach 5 to operate?
ldischler, Sep 23 2005
  

       a footie game?
po, Sep 23 2005
  

       Okay, now I know what an aerospike engine is. I still don't see how it's going to help you stop the back engine from flaming out - you still have to pump the same amount of exhaust past/through it.   

       [po] hang on... <shouts offstage> Edith? Fetch the code book!
moomintroll, Sep 23 2005
  

       Yep, [World] the tube is for the engines. [ldischler], I'm leaving the details to the actual bakers :) and I didn't require an aerospike, just allowed for it.   

       The goal is to put jet engines into a zeppelin in such a way that it wouldn't disintegrate the ship or tear off from it.
theircompetitor, Sep 23 2005
  

       I keep waiting for Jutta to weigh in about trademark infringement or something...
normzone, Sep 23 2005
  

       Would be neat to make this spherical (though technically toroidal, due to the hole), and only have one main engine for thrust. Add another few small engines for rotation, that fire at a tangent to the sphere. Then you'd have a ship that can still wander off in any direction, but performs graceful twists between each motion.
Worldgineer, Sep 23 2005
  

       //The goal is to put jet engines into a zeppelin// Wouldn't there be a goal at each end of the field?
AbsintheWithoutLeave, Sep 23 2005
  

       //I thought aerospike engines required like mach 5 to operate?// You may be thinking of ramjets, I've seen photos of an aerospike firing up while on a stationery test bed.   

       [tc] - Good plan. A jet either side on a stub wing would be cheaper and easier to maintain, but not nearly as cool.
wagster, Sep 23 2005
  

       The intakes for the two central jets (forward / reverse) cannot be the corresponding (reverse / forward) jet nozzles - the physics of jet intakes and exhausts are incompatible. This precludes the central tube idea.   

       Also, airships are not aerodynamicly efficient (more drag than a boy scout gang show) so jet engines would be much less efficient than the traditional arrangement of propeller units in external nacelles.   

       DARPA has a program ("Walrus") that is promoting airships as heavy-lift, quick turnaround capable military units - as far as I'm aware none of the many design and fabrication participants are proposing the use of jet engines, even externally.   

       There are a number of companies in the US and Canada developing airships and most seem to have settled on a spherical design rather than the cigar shape - easier to tether, easier to steer and control at low speeds, better lift to cost ratio.   

       There are some eccentrics on the fringe of the industry [link].
ConsulFlaminicus, Sep 24 2005
  

       Great link, [Consul]! I wasn't implying btw that the exhaust would work in the way you describe -- I was using the "wave my hand, let there be an jet engine there" technique :)
theircompetitor, Sep 24 2005
  

       I can't be the only one who was trying to figure out why Jetta would be flying around.
Almafeta, Sep 24 2005
  

       I think its meant to be jet air ships
chocolateraindrops, Sep 24 2005
  

       Check out the Flying Soccer link, cool.
theircompetitor, Sep 25 2005
  
      
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