What are the different types of exhaust nozzles used on aircrafts?
Principle geometries
- Convergent nozzle. Convergent nozzles are used on many jet engines.
- Divergent nozzle.
- Convergent-divergent (C-D) nozzle.
- Fixed-area nozzle.
- Variable-area for afterburning.
- Ejector.
- Variable-geometry convergent-divergent.
- Additional features.
What is a variable area nozzle?
• Variable area nozzles are used for adjusting. the exit area for different operating conditions. of the engine.
Why do jet engine nozzles open and close?
The nozzle will open or close to give an exit area suitable for the volume of the gas stream, which prevents any pressure increase from occuring in the jet pipe.
How do variable nozzles work?
A variable area nozzle helps to adjust the exit pressure of the combustion gases to ambient pressure. When they leave the turbine, the combustion gases have still some remaining pressure which is converted into speed by a convergent contour of the nozzle.
What makes a variable geometry nozzle more efficient?
The flow is subsonic upstream of the throat, but supersonic downstream of the throat. The variable geometry causes these nozzles to be heavier than a fixed geometry nozzle, but variable geometry provides efficient engine operation over a wider airflow range than a simple fixed nozzle.
Why do rocket engines use variable geometry nozzles?
The variable geometry causes these nozzles to be heavier than a fixed geometry nozzle, but variable geometry provides efficient engine operation over a wider airflow range than a simple fixed nozzle. Rocket engines also use nozzles to accelerate hot exhaust to produce thrust.
Why are nozzles used to deflect exhaust flow?
Recently, however, engineers have been experimenting with nozzles with rectangular exits. This allows the exhaust flow to be easily deflected, or vectored , as shown in the middle of the figure. Changing the direction of the thrust with the nozzle makes the aircraft much more maneuverable.
Why are nozzles important in an airplane engine?
Because the nozzle conducts the hot exhaust back to the free stream, there can be serious interactions between the engine exhaust flow and the airflow around the aircraft. On fighter aircraft, in particular, large drag penalties can occur near the nozzle exits.