h a l f b a k e r y
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See image in link.
Rotor has small triangles with one leg diagonal and one
vertical like in a ratchet, which catch the gasoline/air
mixture. It is ignited only in one place, the combustion
spreading in one direction only.
As it starts burning in a "cycle" the exhaust valve is opened,
thrust is created in that opposite direction of the exhaust
trail pushing the rotor.
When the fuel is burnt, new fuel is pumped in and ignited.
[pashute, Jul 22 2013]
Similar but actually works...
Wave disc engine, uses shockwaves from combustion. [neutrinos_shadow, Jul 22 2013]
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||It appears to me that your diagrams don't show // with one leg diagonal and one vertical like in a ratchet //
||I'm not sure simply having a fixed rachet shape will allow the combustion to travel only one way. The triangles would need to be able to compress when there was pressure on the diagonal leg.
||Alternately you might be able to use a Tesla valve, though those do have some leakage.
||And besides that, I don't see how this would actually work.
||ooh! neutrinos, thanks for the link! scad, say with a
tesla valve why not? And your correct that the
ratchet shape is not shown. I'll fix that.
||The ratchet shape should cause most of the energy
to be directed (reflected) in one direction rather
than the other. Why wouldn't it work? Its similar to
a turbine rotating in an air flow.
||// [pashute] The ratchet shape should cause most
of the energy to be directed (reflected) in one
direction rather than the other. Why wouldn't it
Lets assume the gasoline/air mixture burns
ideally, producing uniform pressure, that leakage
between notches is zero, and that the wheel is
so much bigger than each notch that the
calculationg for curvature can be ignored. For
simplicity, lets assume the angle of the diagonal
walls are 45 degrees.
Consider the inside of one notch consisting of a
vertical and a diagonal wall.
The force on each wall is pressure time area. The
area of the diagonal wall is sqrt(2) time that of the
vertical wall, so the force on it is also sqrt(2) time
that of the vertical wall.
Forces on a wheel have a radial (outward) and
angular (rotating) component. The radial
component of the force on the vertical wall is
zero, the angular one 1 time the force on it.
The radial and diagonal components on the
diagonal wall are both 1/sqrt(2) times the force on
Since the force on the diagonal wall is sqrt(2) that
of the force on the vertical wall, the net radial
force on the wheel from the two walls is zero. So
the wheel wont turn due to it.
||If the exhaust is directed some way other than
straight out, the wheel is simply a fuel-powered
aeolipile similar to the steam powered one Hero of
Alexandria was said to have made ca 50 BC. Burn
enough fuel fast enough, Itll turn, but the
notches inside dont help it.
||For the sake of explanation, I'll add an almost
completely closed wall inside the wheel, just
before the beginning of the burning cycle.
||The exhaust leaves the wheel at this point.
||After filling with fuel and oxygen, that point is
ignited. You are correct that the total force in all
directions will eventually cancel itself out, BUT, at
the first stage, the shock wave hits the vertical
wall pushing the exhaust against that wall.
||The exhaust then exits the wheel from the side,
NOT working as an Aeolipile. The returning force
of the exhaust is now much less in the the
diagonal direction, due to the loss of energy
during the exhaust escape. I hope you agree till
||If I'm correct, then, you can remove the wall, and
just have the single exhaust valve or perhaps
multiple exhaust valves, with the combustion
happening each time inside the next "ratchet"
||- The efficiency could be improved in several
ways, but first lets agree that it would work.
||By the way, today I tried a first version of the
rainbow wind generator. It turned beautifully
when disconnected, but wasn't able to make a 6
volt bicycle dynamo budge.