PH2¶
Parahydrogen is the spin isomer of hydrogen used in cryogenic liquid rocket fuel.
Ordinary H2 is an equilibrium mixture of ortho and para hydrogen. See Wikipedia Spin isomers of hydrogen
The equilibrium balance varies with temperature. Liquid hydrogen consists of 99.79% parahydrogen and 0.21% orthohydrogen mole percent. At the room temperature, it is about 25% parahydrogen and 75% orthohydrogen
Parahydrogen has been and is currently used in the Centaur Stage Series as well as the main propulsion for the Space Shuttle.
Reference Points¶
PH2 == H2(L) == Hydrogen == ParaHydrogen
Hover over column headers to see definitions, values to see alternate units
| Tref | Pref | SG | Cp | dHvap | Visc | Cond | Surf | |
|---|---|---|---|---|---|---|---|---|
| Source | R | psia | g/ml | BTU/lbm-R | BTU/lbm | poise | BTU/hr-ft-R | lbf/in |
| RocketProps | 36.5 | 14.7 | 0.0708 | 2.325 | 191.9 | 1.333e-04 | 0.0598 | 1.100e-05 |
| RefProp | 36.5 | 14.7 | 0.0708 | 2.325 | 191.9 | 1.333e-04 | 0.0598 | 1.100e-05 |
Fluid Properties¶
PH2 == H2(L) == Hydrogen == ParaHydrogen
Hover over column headers to see definitions, values to see alternate units
| MolWt | Tc | Pc | SGc | Zc | Tnbp | Tmelt | omega | |
|---|---|---|---|---|---|---|---|---|
| Source | g/gmole | R | psia | g/ml | (-) | R | R | (-) |
| RocketProps | 2.016 | 59.3 | 186.5 | 0.0313 | 0.3022 | 36.5 | 24.9 | -0.21861 |
| RefProp | 2.016 | 59.3 | 186.5 | 0.0313 | 0.3022 | 36.5 | 24.9 | -0.21861 |
