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Hydroaeropropulsion Rocket Research Labs
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23 april 2002
For this setup, I prepared a wine bottle cork. I found one that just fit
into the opening of a coca cola bottle. With a hand drill, I drilled
a hole through the cork, then screwed a bicycle tire valve through it.
Note that the cork needs to be wet in order to seal well. Dry corks
leak too much. Or why else do you think wine bottles have to be
stored upside down or at least lying horizontally? The cork
we used had een soaking for a whole night.
Trial tests
During the noon, we conducted a few trial tests ...
Geert (on the right) pushing the cork inside the bottle. It's easiest
to do this by pushing the bottle upside down against a solid object
(a pole in our case).
Geert pumping. Pieter (left) is pushing the bottle to the ground.
Here you can see better the (cheap) bicycle pump we use.
When the pressure increases, it gets harder to keep the bottle to
the ground (as you can probably see from the photo :-) )
and some water begins to leak from the cork (which is of course
only designed to seal a bottle of wine at 1 bar!) but the leakage
is small enough for our purposes.
When Pieter lets go of the bottle, it shoots upward (the cork is
shot out of the bottle in the same way as a bottle of champaign) ...
alas, it's difficult to photograph a flying rocket since the whole
flight lasts only a few seconds.
We also tested a 1.5 liter bottle.
Interesting to note is that when the bottles return to the ground,
they're filled with a very fine water vapour; by gently squirting the bottle
some of the vapour can be blown out giving the impression of a white
smoke coming out of the bottle.
The launcher
In the evening, we built a simple launcher [pictures coming soon].
We tested a hundred meters away in a more open area, since two of our
bottles had already landed on the roof during the noon :-)
We did some launches of 0.5 and 1.5 liter bottles, to great success.
It's really spectacular to see how the bottles take off almost
instantly---when thinking of "rocket launch" most people expect
to see a slow lift-off like those real rockets on tv; nothing
of that slow stuff here however :-)