A scramjet (supersonic combustion ramjet) engine is a type of air-breathing jet engine designed for high-speed travel in the atmosphere. Unlike traditional jet engines, scramjets operate at hypersonic speeds and rely on supersonic combustion of fuel with atmospheric oxygen. The thrust force in a scramjet engine can be described using control volume analysis.
The thrust force of a scramjet engine is the forward force generated by the expulsion of high-speed exhaust gases resulting from the supersonic combustion of air and fuel in the engine. Scramjets are specifically designed for hypersonic flight, where the forward motion of the vehicle compresses incoming air without the need for traditional compressors.
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).