THE SMALL CAT TRUCK-2
Favorite little Cat of Eva the Great Princess!
Little bit of math
The truck has been design to use gaz turbine, Hydrogen and it's oxydizer, Oxygen. Let's take a closer look to that concept:
By mass, the ratio of Hydrogen by Oxygen is stoichiometrically 8:1, but in rocketery the NASA use a ratio of 6:1, for ISP(Thrust efficiency) reason:
For this project, I will use the stechio ratio, 8:1. The data of the gaz are:
| Hydrogen | Oxygen | |
| Density | 0.07 g/cm³ | 1.141 g/cm³ |
| Molar Mass | 1 | 16 |
| Boiling Point | 20.271 °K | 90.188 °K |
| Heat of Vaporisation | 0.904 kJ/mol | 6.82 kJ/mol |
| Molar Heat Capacity | 28.836 J/(mol*K) | 29.378 J/(mol*K) |
The most important in this document is resume on this page:
The experimental data give us, from Praxair (a large manufacturer):
As in the text, the magic number is about 15 kwh/kg of liquid Hydrogen. In it's current draft configuration, the tanks of the truck may contain less than 140 L of liquid. In volume, 1 g / 0.07 g/cm³ = 14.28 cm³, and 8 g / 1.141 g/cm³ = 7.01 cm³, and the ratio is 14.28 / 7.01 = 2.04:1. In the tanks, 93L of Hydrogen and 47L of Oxygen.
