Hmm... I presume those specific impulses should be "km/sec" rather than "m/sec"? They seemed on the high side until I noted the expansion conditions they were determined at: 1000 -> 0.2 psia, or 5000:1 pressure ratio...!
(So that's how to get 1.88 km/sec out of H2O2 monoprop and 3.73 km/sec out of LOX-RP1!) Since the subject of the paper was propulsion for planetary missions (which will fly in vacuum), I suppose calculating for such expansion ratios may be appropriate... are they within reach of practical nozzles? -dave w [EMAIL PROTECTED] wrote: > > Gentlefolk, > > For your information, here is a table based on some of Dr. Bob Frisbee's > (yes, he's related to the Frisbee Pie Plate company family which used to > throw the pie plates that evolved into the toy) work at JPL. Bob Frisbee is > still doing his thing at JPL. I added to the table and included it in a > paper "Rocket Fundamentals: A Brief Review/Tutorial" incorporated into an > NSS "White Paper" boosting space in the early nineties. The paper is pretty > basic, but I'll send it on request (It's a Word 5.1 doc, but I can translate > to other formats). The table should be viewed in a non-proportional font, > such as courier or monaco. "Field" refers to actual engine firing data. I > probably have Bob's paper around here somewhere, but it would take days of > digging to find it...(sigh). > > At the AF Rocket Lab (still at Edwards, but I've lost track of > management-ego-trip name changes), we spent considerable time and money > looking at ways of incorporating even a little monatomic hydrogen into > anything with even a little stability. Lots of ab-initio quantum chemistry > calculations on big computers went into this. Null Set. Some folks are > probably still looking. At a more mundane level, when I was there, there > were still some oldtimes at the lab who had lost fingers playing with tiny > quantities of liquid ozone. > > --Best, Gerald > > Table (Isp For Selected Propellants (adapted from Frisbee, 1983) > > PROPELLANT ! SPECIFIC IMPULSE m/s > ! Ideal(1) ! Field (2) > __________________________!___________!___________ > Solids: (IUS(3) �?^ 3.0 m/s) > 10CH2 + 72NH4ClO4 + 18Al ! (4) ! 3.33 > 10CH2 + 52NH4ClO4 + 20Al ! (4) ! 3.40 > 14CH2 + 72NH4ClO4 + 14Be ! (4) ! 3.40 > __________________________!___________!___________ > Monopropellants ! ! > H2O2 (Hydrogen peroxide) ! 2.40 ! 1.88 > N2H4 (Hydrazine) ! 2.64 ! 2.59 > __________________________!___________!___________ > Bipropellants ! ! > ClF5 + N2H4 ! 3.79 ! 3.65 > N2O4 + N2H4 (5) ! 3.96 ! 3.47 > O2 + RP-1 (6) ! 4.52 ! 3.73 > O2 + H2 (SSME) ! 4.97 ! 4.61 > F2 + N2H4 ! (4) ! 4.28 > F2 + H2 ! 5.18 ! 4.91 > __________________________!___________!___________ > Tripropellants ! ! > F2 + H2 + Li(7) ! 6.89 ! (4) > O2 + H2 + Be(7) ! 6.91 ! (4) > __________________________!___________!___________ > Free Radicals (Unstable) ! ! > O3 + H2 ! 5.95 ! 5.01 > H + H ! 20.89 ! (4) > __________________________!___________!___________ > Nuclear Thermal (�?^3500K) ! ! > CH4 ! 6.00 ! (4) > H2 ! 11.00 ! (4) > __________________________!___________!___________ > (1) All chemical energy converted to kinetic energy > (2) Modeled for optimum expansion from 6894 kP to > 1.379 kP (1000 psia to 0.2 psia, 0.014 atmosphere) > (3) Inertial Upper Stage -- a solid fuel upper stage > (4) No Data Provided > (5) Ignites on contact. Typical of Titan main engines > (6) Typical of Atlas and Delta main engine > Reference: Frisbee, Robert, Ultra High Performance Propulsion for Planetary > Spacecraft, JPL D-1184, Pasadena, CA, 1983 _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
