The oxidizer-to-fuel (O/F) ratio for liquid propellant rockets is a fundamental parameter that determines the proportion of oxidizer to fuel used in the rocket’s propulsion system. In liquid rocket engines, the oxidizer and fuel are stored in separate tanks and are combined in a combustion chamber for combustion. Achieving the correct O/F ratio is essential for efficient and controlled combustion. Here’s how you can calculate it using SI units:
The mole-based O/F ratio (ξ) is calculated by dividing the moles of oxidizer (n_ox) by the moles of fuel (n_fuel). You’ll need the molar masses of the oxidizer and fuel, which should be in grams per mole (g/mol) to ensure consistency:
where,
- ξ is the mole based oxidizer to fuel ratio
- nox in the number of moles of oxidizer
- nfuel is the number of moles of fuel