Pulsejet engines are a type of air-breathing jet engine that operate by periodically opening and closing a combustion chamber. They are known for their simple design and have been used in various applications, including model airplanes, target drones, and cruise missiles. However, pulsejet engines are not typically analyzed using control volume analysis in the same way as traditional jet engines. Instead, their operation is often described by considering the cyclic combustion process.
A pulsejet engine operates by periodically allowing air to enter a combustion chamber, igniting the fuel-air mixture, and then closing the combustion chamber to produce thrust. The repeated pulsing or cycling of this process generates thrust for propulsion.
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).