Specific Impulse for a liquid propellant rocket nozzle is a crucial performance parameter that quantifies the efficiency with which a liquid rocket engine converts propellant into thrust. It measures the impulse (thrust multiplied by time) produced per unit mass of propellant expended, providing a key metric for comparing rocket engines.
The specific impulse of a liquid propellant rocket nozzle is influenced by factors such as the specific composition of the propellants, combustion efficiency, and the design of the rocket nozzle. Unlike solid rocket motors that burn their propellant in a single event, liquid rocket engines allow for more precise control of the combustion process, enabling adjustments in thrust and specific impulse during operation.
It is defined as the thrust generated per unit of propellant expended and is expressed in seconds.
where,
- is the specific impulse of the rocket engine (in seconds, s)
- F is the Thrust Produced
- ṁ is the mass flow rate of propellant in KG/Sec
- g0 is the acceleration due to gravity