The total energy at the nozzle exit of a rocket is the sum of the kinetic energy and the specific enthalpy of the exhaust gases per unit mass. This energy represents the energy content of the exhaust gases as they leave the rocket nozzle. In the context of rocket propulsion, it is often expressed in terms of specific energy, which is the energy per unit mass of the exhaust gases.
In terms of specific energy (), which is the total energy per unit mass, the formula becomes:
Where:
- is the specific energy (total energy per unit mass),
- is the specific enthalpy, (Joules per kilogram (J/kg))
- is the velocity of the exhaust gases, (Meters per second (m/s))