Ral123
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Two "gear pumps" as an internal combustion engine
There are many new internal combustion engine designs. When power to weight ratio is crucial, the rockets use turbines(to power the main pumps of
their liquid fuel engines), in the simple case they are pressure fed with moderately powerful monopropellant.
Cant we put two gear pumps(http://en.wikipedia.org/wiki/File:Gear_pump.png) and get the efficiency of a diesel engine in a smooth working very compact package?
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IrC
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Quote: Originally posted by Ral123  | There are many new internal combustion engine designs. When power to weight ratio is crucial, the rockets use turbines(to power the main pumps of
their liquid fuel engines), in the simple case they are pressure fed with moderately powerful monopropellant.
Cant we put two gear pumps(http://en.wikipedia.org/wiki/File:Gear_pump.png) and get the efficiency of a diesel engine in a smooth working very compact package?
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While most big trucks today use turbines, for decades many had 8:71 blowers. Nothing new. If you are talking fuel pump, that idea was also old in the
70's. Very dangerous, a belt driven gear type fuel pump. Caused many a disaster back in the day. I know as drag racing was a hobby of mine long ago.
The car I drove on the street every day did 10.82 seconds at 147.3 MPH in the quarter mile in it's first run at International Speedway back in 1973.
They had a racing class where people could drive in off the street and drag race. Even more fun was driving back home from East St Louis to Lake of
the Ozarks with both 4" headers left in the trunk.
http://en.wikipedia.org/wiki/Supercharger
http://en.wikipedia.org/wiki/Roots-type_supercharger
"Science is the belief in the ignorance of the experts" Richard Feynman
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bfesser
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<a href="http://en.wikipedia.org/wiki/Wankel_engine" target="_blank">Wankel engine</a> <img src="../scipics/_wiki.png" />
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IrC
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Hey I forgot about that one. Brings back memories of big stories decades ago about how we were all going to be running them in ten years, but by the
80's the seal problems were still unsolved for everyday commercial production. IIRC (but I could have just read they wanted to but didn't), I remember
limited production of a car that spent it's days in recall shops. Did not read that whole wiki but did they ever solve that problem?
"Science is the belief in the ignorance of the experts" Richard Feynman
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Ral123
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What makes a centrifugal or inline turboprop more efficient engine then the idea with two gear pumps-one is the compressor and the other at the
exhaust with combustion chamber between them?
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froot
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Gear pumps by design are perfectly suited for high pressure applications because back pressure won't reverse the pump if the drive ceases, meaning
that the drive won't need to overcome back pressure before it can start feeding more media in the intended direction of flow. So, if you connect 2 of
these with a combustion chamber in between all you'll achieve is an elaborate pipe bomb because any pressure generated will not flow through and
rotate any of the gear pumps. Gear pumps are also best suited for media with lubricating properties such as oil because of the tight tolerances with
which the parts are made. If you run a hydraulic gear pump dry in air it will seize in minutes rendering it unusable.
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Ral123
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| Quote: Originally posted by froot | | Gear pumps by design are perfectly suited for high pressure applications because back pressure won't reverse the pump if the drive ceases, meaning
that the drive won't need to overcome back pressure before it can start feeding more media in the intended direction of flow. So, if you connect 2 of
these with a combustion chamber in between all you'll achieve is an elaborate pipe bomb because any pressure generated will not flow through and
rotate any of the gear pumps. Gear pumps are also best suited for media with lubricating properties such as oil because of the tight tolerances with
which the parts are made. If you run a hydraulic gear pump dry in air it will seize in minutes rendering it unusable. |
Thanks for the answer, it's really logical about the lubrication part, but isn't that how superchargers work? Also I don't see how such pump wont spin
under pressure, but yes, maybe it will overheat and wear, because normally friction is not nice in the jet engine speeds and temperatures.
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bfesser
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Thread Pruned
20-2-2014 at 13:18 |
bfesser
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Thread Split
20-2-2014 at 13:21 |
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