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#21
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an idea for your ridicule
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#22
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an idea for your ridicule
Sander Vesik writes:
Henry Spencer wrote: The latter. If memory serves, even at SSME pressures, flame temperature is limited more by dissociation of the reaction products than by energy available. To put extra energy into the exhaust of a good rocket engine, you need to use non-thermal means. (Running an electromagnetic thruster on the exhaust of a NERVA, with the reactor supplying the power, has been suggested.) Would "microwaving" the output of a LOX/LH2 engine work? After all, the exhaust is water, and you already have fast-spining turbopumps powered by gas turbines to which you only need to attach more stuff. Or is this a crackpot idea? There are these two annoying things called the Fisrt and Second Laws of Thermodynamics. The First Law implies that the energy for "microwaving" the exhaust has to come from somewhere. Since the only source of energy in a chemically fueled vehicle is the chemical fuel, running some of the propellant through a gas-turbine generator takes propellant away from the main engine, decreasing the amount of potential thrust-producing reaction mass available, which cuts into the total impulse. Furthermore, the Second Law of Thermodynamics guarantess that the amount of energy re-injected into the jet by the "microwaving" process must _ALWAYS_ be less than if you'd simply burned the propellant in the engine in the first place. Hence, your proposal actually _hurst_ performance two ways, unless you have some magic lightweight source of non-chemical energy available to heat the propellant... -- Gordon D. Pusch perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;' |
#23
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an idea for your ridicule
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#24
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an idea for your ridicule
In article ,
James G wrote: I'm not a chemist, or paid much attention in class... What if you could find two stable hydrogen bearing molecules that when combined, released a pair of temporarily free H which combined? I don't think this works, alas -- it's seriously uncommon to find anything that will release free H. -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
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