On Aug 27, 2009, at 10:48 AM, John Heath wrote: > On boeard electrolysis of water to produce Hydrogen/Oxygen rocket > fuel. > > An most interesting paper on the subject at > https://e-reports-ext.llnl.gov/pdf/236614.pdf > It does work in space.
Well, using a URFC for the electrolytic separation takes care of most of the ullage and gas separation problems I mentioned in an earlier post. (And having arrived at that solution independently, I'm convinced it's a viable research path if nothing else. ;) It also has the benefit of being able to turn the separated H2 and O2 back into water and electrical power (minus losses, of course) if needed -- not sure what additional support systems that would need, but it's a tantalizing side benefit. Storing the water still requires some means of eliminating unnecessary headspace in the water tank to avoid the requirement for ullage -- I'm still partial to the idea of a sylphon-type bellows inside a slightly larger tank pressurized with helium or nitrogen -- to maintain water flow into the FC. And as before, these are *not* hypergolic fuels, so using them in engines still requires exactly timed valve opening/closing rates and synchronization between fuel/oxidizer valves and ignition on startup, which are considerably more complex systems than the ones used to control hypergolic engines and RCS thrusters. (All a hypergolic engine has to do is open and close the fuel/oxidizer valves at the right rates and relative timings.) That being said, it's an intriguing idea. Regenerative fuel cell based electrolysis is pretty interesting in and of itself. :) _______________________________________________ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
