h a l f b a k e r yWhy did I think of that?
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Rockets are very wasteful when operated in the lower
atmosphere (up to, say, 100,000ft); this is even truer of single-
stage rockets that must use the same rocket nozzle in air as
they do in space.
Meanwhile, propellors and rotors are actually a fairly efficient
way of generating thrust/lift
in air, which is why helicopters
work to some extent. So, just build the rocket with two huge
rotor blades fixed to the body. Offset the thrust of the rocket
engines very, very slightly so as to induce spin. Hey presto,
your rocket will literally screw itself into the air, and you still
get almost all of the direct rocket thrust besides.
At some point, it will be advisable to jettison the blades,
preferably all at the same time.
Focke-Wulf Triebflügel
https://en.wikipedi...lf_Triebfl%C3%BCgel
Never got off the drawing board, let alone the ground ... [8th of 7, Jan 21 2019]
Some cultures get all the fun...
https://ca.video.se...81484b7&action=view
[2 fries shy of a happy meal, Jan 21 2019]
Like this...
https://en.wikipedi.../wiki/Rotary_Rocket
The Roton. [neutrinos_shadow, Jan 21 2019]
Sceince rap
https://youtu.be/SFs9VX4zv7g
not that great [not_morrison_rm, Jan 22 2019]
[link]
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As you should have expected, the Prior Art in this area belongs to the Nazis, and is the distinctive Focke-Wolf Triebflügel tailsitting VTOL fighter. |
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Ooh, you'll like this then. [link] |
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There was the Roton concept, which is like this. But you
keep the rotor blades for landing.
It wasn't very good. |
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Re. third link: Bloody typical. Every time I invent something,
some bastard goes and pre-empts me. |
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I'm beginning to wish I won't have made my time-machine
plans available online. |
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I'm thinking the astrodog will get dizzy. |
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Materials will only get stronger, fuel density will only get higher, peer reviewed science won't accept anything else. |
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I always wondered why a rocket tries to thrust a volume that is leaving at thrust speed rather than turning slightly to thrust against the more turbulent, and in my mind, harder expansion edge. |
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// I always wondered why a rocket tries to thrust a
volume that is leaving at thrust speed rather than turning
slightly to thrust against the more turbulent, and in my
mind, harder expansion edge. // |
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That sounds like it could be an interesting theory, but
unfortunately I don't have the background info to know
what you're talking about. Could you further explain (or
provide links explaining) what you mean by // thrust a
volume that is leaving at thrust speed // and //
expansion edge // |
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[wjt] is confusing a rocket - which works purely by momentum transfer - with a jet - which generates "pressure" at its outlet. |
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This is the reason that rockets work in vacuum, but turbojets don't (quite apart from the lack of air as a working fluid). |
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The other Thrust definition, To push or drive quickly and forcefully |
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The area between the ground and the edge of space has atmosphere. Which is more pushing out a ball or pushing on a ball that is pushing on a wall? It seems the rocket could use the atmosphere rather than fight it.
Using only momentum transfer seems the ultimate in cavitation. |
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//Every time I invent something, some bastard
goes and pre-empts me.// Never mind. You could
always just invert your idea and invent the rocket
powered corkscrew. No one has pre-empted that
one. (oh wait - I just have!) Poor Max |
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I tried that once, set fire to the dust bag, they ain't
cheap you know. |
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Reading further down the Rotary Rocket wiki
I came across "A full size, 63 ft (19 m) tall,
Atmospheric Test Vehicle (ATV) was
built under contract by Scaled Composites"... and it
rose to a shocking 75ft on the last go. |
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Now, if the ATV had been situated somewhere on
Earth that is 74 foot from vacuum, they'd all be
tootling around in gold-plated Rolls-Royces by now.
It's the little details... |
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Anyway, I was looking for the Science:Rapping and
der ain't one. |
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//situated somewhere on Earth that is 74 foot from vacuum//
How about 23 metres outside Milton Keynes? |
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Is Milton Keynes named after John Milton or the
famous baby bottle bleach brand? |
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It's actually named for Milton Berle and Skandar Keynes. |
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Odd, we had the suspicion that John Maynard Keynes was somehow involved; something to do with the ability of economists to instantly suck all the oxygen out of the atmosphere ... |
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// tried that once, set fire to the dust bag, they ain't cheap you know. // |
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Worse, if you try it with a Dyson, it melts, and the parts are ludicrously expensive. |
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// they'd all be tootling around in gold-plated Rolls-Royces by now. // |
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Strange as it may seem, Burt Rutan actually has things (many of which he designed) that are more fun than a gold-plated Rolls-Royce. |
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Taking the economist view, is there such a thing as a stoichiometric reaction specific impulse? Does it's numbers scale up with the measured macro specific impulse or is it a sum greater than parts kind of deal, impulse of an impulse? |
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