Types Flashcards
(17 cards)
How many types of compressors are there?
3
What are the 3 types of compressors?
Centrifugal flow, axial flow, centrifugal-axial flow
Explain the centrifugal flow compressor.
Compression is achieved by accelerating air outward perpendicular to the longitudinal axis
Explain the axial-flow compressor.
Compresses air by a series of rotating and stationary airfoils moving the air parallel to the longitudinal axis
Explain the centrifugal-axial flow compressor.
Uses both, centrifugal and axial compressors to achieve the desired compression
How many types of turbine engines are there for aircraft?
4 - turbojet, turboprop, turbofan, turboshaft
How many sections does a turbojet consist of?
4 - compressor, combustion chamber, turbine section, and exhaust
Explain the sequence of how the turbojet engine works.
Compressor section passes inlet air at a high rate of speed to the combustion chamber.
Combustion chamber contains fuel inlet and igniter for combustion.
Expanding air drives a turbine, which is connected by a shaft to the compressor, sustaining engine operation.
Accelerated exhaust gases from the engine provide the thrust.
What’s a turboprop engine?
A turbine engine which drives a propeller through a reduction gear
Explain the process of how a turboprop engine works.
Exhaust gases drive a power turbine connected by a shaft that drives the reduction gear assembly
Why is reduction gearing necessary in a turboprop engine?
Optimum propeller performance is achieved at much slower speeds than the engines operating RPM.
Why were turbofans developed?
Combines the best features of a turbojet and a turboprop.
How are turbofan engines designed to develop more thrust?
By diverting a secondary airflow around the combustion chamber
What is the benefit of bypass air?
Generates increased thrust, cools the engine, and aids in exhaust noise suppression.
Allows for turbojet-type cruise speed with lower fuel consumption.
Generally, how many times is the inlet air divided in a turbofan engine?
At least 2 separate streams of air.
What is the purpose of separating the inlet air in a turbofan engine?
One stream will pass through the engine core, while a second bypasses the engine core.
What does “bypass ratio” refer to?
The ratio of the mass airflow that passes through the fan divided by the mass airflow that passes through the engine core.
