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21 Cards in this Set
- Front
- Back
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What are the two basic sections of a turbine engine ? |
The hot and cold section. |
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What are the two basic types of compressors that are used in aircraft turbine engines ? |
Axial-flow and centrifugal. |
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What is the purpose of the stators in an axial-flow compressor ? |
The stators convert some velocity energy into pressure energy and change the direction of the air so it is proper for the next stage of rotors. |
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What are three types of combustors used on aircraft turbine engines ? |
Can-type, annular-type, and Can-annular-type. |
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How many igniters are there normally in an aircraft turbine engine ? |
Two |
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What is the main purpose of the turbine nozzle in an aircraft turbine engine ? |
The turbine nozzle directs the hot gases as they leave the combustors so they will turn the turbine wheel with maximum efficiency. |
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What is meant by a free-turbine tubroshaft engine ? |
A turboshaft engine that has a turbine wheel, or stage of turbine wheels, that is not used to drive the compressor of the gas generator section of the engine. This free turbine drives the propeller in a turboprop engine or the transmission and rotor of a helicopter. |
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Why do some axial-flow turbine engines have more then one set of turbines and compressors ? |
A two-spool turbine engine has a low-pressure and a high-pressure compressor, each driven by its own turbine. The two independent systems operate at the speed at which they are most efficient. |
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What kind of bearings are used to support the rotor shaft of an aircraft turbine engine ? |
Anti-friction bearings, such as ball bearings or roller bearings. |
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What is meant by a turbofan engine ? |
An axial-flow turbine engine in which the first stage of compressor bladed are lengthened, so they can force air around the outside of the gas generator portion of the engine. |
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Where can you find the limits of repair allowed for the compressor blades of an aircraft turbine engine ? |
In the FAA-approved service manual issued by the manufacturer of the engine. |
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Why is it important that a turbojet engine be allowed to cool before it is shut down after it has been operated at a high power setting ? |
If the engine is shut down while it is hot, there is a possibility that the shroud will contract around the turbine wheel and seize the rotor. |
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What is meant by a hung start in a turbine engine ? |
A start in which ignition occurs, but the engine does not accelerate to a self-sustaining speed. |
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What is meant by a hot start in a turbine engine ? |
A start in which ignition occurs, but the internal temperatures go high enough that they can damage the engine. |
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What is meant by creep of the turbine blades ? |
A condition of permanent elongation of the turbine blades. Creep is caused by the high temperatures and the high centrifugal loading impose d on the blades. |
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How is the compressor of a turbine engine cleaned ? |
An emulsion-type cleaner is sprayed through the engine while it is being motored by the starter or operated at a low speed. The wash is followed by a clean water rinse. |
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Where is water injected into a turbine engine for cooling purposes ? |
Into the compressor inlet and into the engine diffuser case. |
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At what point in a turbine engine is the temperature the highest ? |
At the inlet to the high-pressure turbine. |
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What is the function of the interconnect tubes between the cans of a turbine engine that uses can-type combustors ? |
These tubes allow the flame to travel from the cans that contain the igniters to all of the other cans when the engine is being started. |
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What are two types of thrust reversers that are used on turbojet engines ? |
The mechanical blockage-type and the aerodynamic blockage-type. |
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What is meant by trimming a turbojet engine ? |
Adjusting the fuel control to get the correct idling and maximum-thrust RPM. |
