A turbofan engine is a type of aircraft propulsion system that combines elements of both turbojet and turboprop engines. It consists of a core gas turbine engine (similar to a turbojet) and a fan, which provides additional thrust. The thrust force of a turbofan engine is generated by the combination of jet thrust from the core engine and additional thrust from the fan.
The thrust force of a turbofan engine is the forward force produced by the expulsion of high-speed exhaust gases from the core engine and the accelerated air from the fan. The core engine provides high-speed exhaust gases, while the fan accelerates a larger mass of air at a lower velocity, contributing to the overall thrust of the engine.
The thrust equation for a turbojet engine using control volume analysis is expressed as:
where,
- is the thrust force,
- ṁe is the mass flow rate of exhaust gases in kilograms per second (kg/s).
- is the Exhaust velocity at the nozzle exit in meters per second (m/s).
- ṁ0 is the mass flow rate of inlet gases in kilograms per second (kg/s).
- is the Exhaust velocity at the nozzle Inlet in meters per second (m/s).
- is the Pressure at the nozzle exit in pascals (Pa).
- is the Pressure at the nozzle inlet in pascals (Pa).
- is the Area of the nozzle exit in square meters (m²).