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

_images/OrthoParaEquil.jpg

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
SourceRpsiag/mlBTU/lbm-RBTU/lbmpoiseBTU/hr-ft-Rlbf/in
RocketProps36.514.70.07082.325191.91.333e-040.05981.100e-05
RefProp36.514.70.07082.325191.91.333e-040.05981.100e-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
Sourceg/gmoleRpsiag/ml(-)RR(-)
RocketProps2.01659.3186.50.03130.302236.524.9-0.21861
RefProp2.01659.3186.50.03130.302236.524.9-0.21861

Vapor Pressure

_images/PH2_Psat.png


RocketProps Selected Curve

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Density

_images/PH2_SG.png


RocketProps Selected Curve

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Heat Capacity

_images/PH2_Cp.png


RocketProps Selected Curve

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Viscosity

_images/PH2_Visc.png


RocketProps Selected Curve

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Heat of Vaporization

_images/PH2_Hvap.png


RocketProps Selected Curve

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Thermal Conductivity

_images/PH2_Cond.png


RocketProps Selected Curve

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Surface Tension

_images/PH2_Surf.png


RocketProps Selected Curve

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