Types of Gas Turbine Engines Flashcards
in a turbojet, the difference in velocity in the inlet and exit produces ______
thrust
What is EPR?
engine pressure ratio
the ratio of turbine discharge pressure to the inlet air pressure
engine pressure ratio (EPR)
When a compressor and turbine are joined on one shaft, the unit is called a _______.
spool
The resultant increase in temperature causes a substantial ______ in volume.
increase
A gas turbine engine that delivers power to a propeller is referred to as a ________.
turboprop engine
Turboprop engines are similar in design to turbojet engines except that the power produced by a turboprop engine is delivered to a __________ that spins a propeller.
reduction gear system
Reduction gearing is necessary in turboprop engines because optimum propeller performance is achieved at much ________ than the engine’s operating rpm.
slower speeds
Most turboengines provide the best ________ of any GTE.
specific fuel consumption
The output from a turboprop engine is the sum of the shaft horsepower developed at the turbine, and the residual jet thrust. What is this called?
Equivalent Shaft Horsepower (ESHP)
In turboprop, almost all the energy in the gas stream is converted into mechanical power, to drive both the _______ and the ______.
compressor, propeller
A gas turbine engine that delivers power to a shaft that can drive something else is referred to as a ________.
turboshaft engine
GTE widely used as APUs
turboshaft
Output of a turboprop or turboshaft engine is measured by ________ rather than thrust.
shaft horsepower
Most ______ engine incorporates a free power turbine.
turboshaft
In a turboshaft, it throws the air out radially so that it can enter the combustion chamber in the correct direction.
centrifugal compressor
The first stage turbine drives the ______ and the free power turbine converts any remaining energy to mechanical energy.
compressor
A ______ engine consists of a multi-bladed ducted propeller driven by a GTE.
turbofan
They were developed to provide a compromise between the best features of the turbojet and the turboprop.
turbofans
the airlines’ choice
turbofan
engines that have the fan mounted in front of the compressor
forward-fan engines
turbofan engines that have the fan mounted to the turbine section
aft-fan engines
three terms to be familiar with in a bypass engine
- thrust ratio
- bypass ratio
- fan pressure ratio
It is a comparison of the thrust produced by the fan to the thrust produced by the engine core exhaust.
thrust ratio
