4 ms·
Eh, I wouldn't say that a balloon floats without much air resistance. Trying to throw one to someone else is difficult, for example. The cheap footballs that a
by esotericn 7y ago
Eh, I wouldn't say that a balloon floats without much air resistance. Trying to throw one to someone else is difficult, for example.
The cheap footballs that are thin skinned - we used to call them 'flyaway' balls when I was younger. Because even those, substantially heavier than a balloon, would go off in random directions due to their susceptibility to wind from the low weight.
But actually, I've never thought of a zeppelin this way before. It gives a good intuition - but for the opposite reason you've stated, that they _do_ act kind of like balloons, and that's not what you want from a directed vehicle!
- MayeulC 7y ago> Because even those, substantially heavier than a balloon, would go off in random directions due to their susceptibility to wind from the low weight. Just be sure to keep in mind that while zepperlins, dirigibles and aerostats are subjected to non-negligible amounts of buoyant force due to low density, that does not make them light, nor easy to push around. If you carry 20kt of cargo, plus the weight of the vehicle (including the weight of the lifting gas), I don't think a wind gust would blow you away, regardless of how strong it is. Try to push around a big buoy, that gives an idea of the challenge. Moreover, spheres are one of the aerodynamically poorest shapes (if not the most), actually worse than a flat sail. That's probably the biggest reason for Zeppelin's shape (or the rugby ball, for that matter).
- dredmorbius 7y agoBalloons are drift bodies rather than directed bodies (blimps, dirigibles). The only control is elevation, via dropping ballast, releasing gas, or application or gradual loss of heat (for hot-air / heated-gas balloons). Otherwise, it's your drag itself that's providing directional control by way of winds.