Propulsive efficiency density is a metric used to evaluate the efficiency of a propulsion system. It represents the amount of useful propulsive power generated per unit mass flow rate of propellant consumed. In other words, it quantifies how effectively a propulsion system converts the energy stored in its propellant into useful thrust for propulsion.
Where:
- is the propulsive efficiency density,
- is the useful propulsive power (thrust times velocity),
- Ë™ is the mass flow rate of the propellant.