A ramjet engine operates on the principle of supersonic combustion of air. Unlike traditional jet engines, a ramjet does not have rotating components like compressors or turbines. Instead, it relies on the forward motion of the aircraft to compress incoming air, mix it with fuel, and then combust it to produce thrust. The thrust force in a ramjet engine can be described using control volume analysis.
The thrust force of a ramjet engine is the forward force generated by the expulsion of high-speed exhaust gases resulting from the combustion of air and fuel in the engine. Ramjets are particularly effective at high speeds, where they can take advantage of the compression of incoming air due to the forward motion of the aircraft.
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).