That's pretty consistent with the first paper, which only claimed a rocket chamber temperature of ~6,000K for pure metallic hydrogen. Diluting it with LH2 or water was just an idea to reduce the temperature to something more manageable, at the cost of specific impulse.
Can't do the calculations myself, but it would surprise me to find that STP chemical bond calculations still apply at 5 million atmospheres, with electrons squeezed out from between the hydrogen nuclei and freely roaming metal. (The metastability must be some kind of collective interaction, like the high temperature superconductivity metallic hydrogen is also often predicted to possess) Another amateur take on it: all that squeezing must put quite a bit of energy into the hydrogen, that wasn't there at the start. > On Jan 27, 2017, at 00:01 , Brent Meeker <meeke...@verizon.net> wrote: > > First, the H atoms in metallic hydrogen are already bound to other H atoms, > so you don't get that H+H=H2+436kJ/mol. Second, H2+O=H2O+517kJ/mol. Since a > mol of water is 9 times as heavy as a mol of H2 it's sonic velocity is 3 > times lower. So even if you could take advantage of the H+H reaction the Isp > would only be 3 times as high. Still far lower than nuclear rocket and 52e3K. > > Brent > > On 1/26/2017 8:05 PM, Hans Moravec wrote: >> I think the intent is that metallic hydrogen alone is the fuel, >> as a metastable way of storing some fraction of atomic >> hydrogen recombination energy. H + H -> H2 at 52,000K >> >>> On Jan 26, 2017, at 20:51 , Brent Meeker <meeke...@verizon.net> wrote: >>> >>> Makes no sense. Isp it just exhaust velocity which depends on the energy >>> release per molecule of the combustion products. The energy per H2O >>> molecule isn't going to be any different when the H came from metallic >>> instead of liquid hydrogen. Having metallic hydrogen might make the rocket >>> structurally more compact and lighter, but don't see how it can raise the >>> combustion temperature of the Isp. >>> >>> Brent >>> >>> On 1/26/2017 4:24 PM, Hans Moravec wrote: >>>> Something like antimatter propulsion, but much easier? >>>> >>>> Metallic hydrogen: The most powerful rocket fuel >>>> http://iopscience.iop.org/article/10.1088/1742-6596/215/1/012194/meta >>>> >>>> Hydrogen Squeezed Into a Metal, Possibly Solid, Harvard Physicists Say >>>> https://www.nytimes.com/2017/01/26/science/solid-metallic-hydrogen-harvard-physicists.html >>>> >>>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Everything List" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to everything-list+unsubscr...@googlegroups.com. >>> To post to this group, send email to everything-list@googlegroups.com. >>> Visit this group at https://groups.google.com/group/everything-list. >>> For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
