| Propellant Heats of Formation, Hydrogen Atoms, Oxygen Atoms & Densities | ||||
| Propellant | Heat of Formation ( J / kmol ) | Hydrogen | Oxygen | Density ( kg / m^3 ) |
| Water | -285,830,000 |
2 |
1 |
997.000 |
| Water at 373 K | -280,183,000 |
2 |
1 |
958.400 |
| Water at 394 K | -278,600,000 |
2 |
1 |
944.000 |
| Water at 452 K | -274,240,000 |
2 |
1 |
903.000 |
| Water at 531 K | -268,310,000 |
2 |
1 |
848.000 |
| Water at 624 K | -261,290,000 |
2 |
1 |
784.000 |
| Steam at 373 K | -239,300,000 |
2 |
1 |
0.588 |
| Steam at 394 K | -238,595,000 |
2 |
1 |
0.557 |
| Steam at 452 K | -236,647,000 |
2 |
1 |
0.485 |
| Steam at 531 K | -233,995,000 |
2 |
1 |
0.413 |
| Steam at 624 K | -230,872,000 |
2 |
1 |
0.351 |
| Hydrogen | -8,123,000 |
2 |
0 |
70.800 |
Propellant hydrogen is the number of hydrogen atoms in a propellant molecule. Propellants that are high in hydrogen generally have a lower density than propellants that are low in hydrogen.
Propellants high in hydrogen are used when high exhaust velocity is important, for instance, electrically heated low thrust rockets for use in space. Propellants low in hydrogen are used when high thrust is important, for instance, water injected rockets operating at low altitude. Propellant hydrogen is used to calculate oxidizer mix hydrogen, propellant molecular and propellant oxidation.
oxidizer mix hydrogen = oxidizer mix * oxidizer hydrogen + propellant mix * propellant hydrogen
propellant molecular = propellant hydrogen + 16 * propellant oxygen
propellant oxidation = 2 * propellant oxygen - propellant hydrogen
This is used in tripropellant rocket, pumped rocket and rocket cost.
Rocket