h a l f b a k e r yKeep out of reach of children.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Thinking of balloons that are planes, wind mills that are balloons, I was wondering if there is a long formula for lift that includes all types of flight.
My second thought was this formula would be like a Drake formula for lift ( >= kg of craft) that just had all the terms which would be zero if
the craft didn't use/involve that term. Terms would include ones for rockets f(directional impulse), balloons f(buoyancy),
planes/rotors f(aerofoils), lifters f(ionic wind). Have I missed any?
My initial thought that brought on this weird line of thinking was, is a plane a balloon. The forward velocity of a wing changes air pressure, a change in air pressure means a change in density which is very balloon like. Thinking like this, means there might be a calculation to covert air volume wing shape and velocity into a plane buoyancy measurement therefore folding the separate plane calcs and balloon calcs into one formula. If this is possible, can other craft be folded in generating a Grand Unified Formula of Flight.
Of course, the G.U.F.F. will have to be re-written when Plank's bit is found and gravity manipulators are prototyped.
Please log in.
If you're not logged in,
you can see what this page
looks like, but you will
not be able to add anything.
Destination URL.
E.g., https://www.coffee.com/
Description (displayed with the short name and URL.)
|
| |
Aw crap, whatever, I've given this a bit of thought too.
In the same way that nobody has ever thought of internally ballasting an Archemedian screw for underwater, they also haven't realized that the same concept carries over to all fluid mediums such as air and if Zepplins were screw shaped and rotated above the gondola, (or beter yet were torus shaped and inverted while rotating around the gondola... but that's another daydream), then the lifting body 'becomes' the propulsion system. |
|
| |
The reverse should also be true of buoyant turbines.
Why design rigid fixtures which experience catastrophic failure when subjected to extremes?
A buoyant screw with a swivel turbine attached to a rigid tower on a circular horizontal track would work in chaotic conditions and allow for increasing or decreasing its size to compensate for increases and decreases in airflow. |
|
| |
Stationary windmills make no sense to me. |
|
| |
How about F=U/D, where F is flyability, U is upth and D is
downth. F>1 means it'll fly. |
|
| |
// if Zepplins were screw shaped and rotated// The thing I
don't get is that propellors were initially multi-turn helices,
but were found to be more efficient as the helices got
shorter, down to the point of being blades a fraction of a helix
long. I don't see why the same physics doesn't apply to your
gizmo. I agree, it seems intuitively that a long helix should
give more "grip" than a short propellor, but I don't understand
why the physics falsifies that in one case but not the other. |
|
| |
<shrugs>
No matter how efficient a propeller gets it is still attempting to either push or pull an object through a resisting medium using another object.
By making the entire craft its own rotating helical shape that resistance becomes instead a parting of the medium which then collapses with the same energy it took to part and, much like a screw through wood, only the thread angle, pitch, and rate of rotation determines how fast the screw will penetrate.
Increased density of the medium becomes a good thing then as less dense mediums such as air will have... slippage when changing rotational speeds. |
|
| |
Yes, that's my thinking too, but then if that were right the
same arguments should apply to propellors, and a long,
multiturn helical propellor would be more efficient than a
bladed propellor. So, there's something missing somewhere. |
|
| |
My guess would be that it's more like an impeller than a propeller, space saving requirements, turning radius of the craft, and whether using a fan or a long screw you're still basically trying to shove a box through water or air.
Nobody ever thought to internally ballast one so that the entire craft is the screw, and nobody's ever thought to scale it up to the size of zeppelins before. |
|
| |
What I can't figure out though is; would beefing up the outer shell to withstand cetrifugal forces offset the weight of swapping out massive engines and props for a small-ish electric motor and an infinitely variable transmission?
Would a zeppelin weigh more or less if it was its own prop? |
|
| |
helicopters are certainly mechanical balloons. They manually decrease density above them, so they can float. |
|
| |
Rockets do the opposite, they rest atop an increasing balloon of hot stuff. Well, when in an atmosphere. |
|
| |
I don't know about you guys, but I don't take any guff from
anyone. |
|
| |
//I don't take any guff from anyone// This would make exchange in a society very difficult but at least the weight would be off. |
|
| |
[Max] Where's the working and units? Could upth and downth both be functions of slipperiness. Flying is not possible if your stuck fast. |
|
| |
Seems like a call for list, but maglev? hovercraft? |
|
| |
"The thing I don't get is that propellers were initially
multi-turn helices, but were found to be more efficient as
the helices got shorter, down to the point of being blades
a fraction of a helix long"; this reminds me so much of
power transmission with a circularly polarized wave and a
polarized antenna I am amazed. |
|
| |
//have I missed any//
laser tweezers and laser tractor beams work in fluid, I
think they would work in air as well; macroscopically this
is light (photon) propulsion at spacecraft. |
|
| |
Buoyancy is X. Upwards force is Y. Gravity is Z. If X+Y>Z, the craft will rise. All active lift can be treated the same here, whether it's from a rocket or deflected air. If buoyancy is negative this still works. |
|
| |