Term
| what are two basic sections of a turbine engine? |
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Definition
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Term
| what are the two basic types of compressors that are used in aircraft turbine engines? |
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Definition
| axial flow and centrifugal |
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Term
| what is the purpose of the stators in an axial flow compressor? |
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Definition
| convert some velocity energy into pressure energy and change the direction of the air so it is proper for next stage of rotors |
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Term
| what are three types of combustors used on aircraft turbine engines? |
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Definition
| can-type, annular type, and cannular-type. |
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Term
| How many igniters are there normally in an aircraft turbine engine? |
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Definition
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Term
| what is the main purpose of the turbine nozzle in a turbine engine? |
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Definition
| directs the hot gasses as they leave the combustors so that they will turn the turbine wheel with maximum efficiency |
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Term
| what is meant by a free-turbine turboshaft engine? |
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Definition
| A turboshaft engine that has a turbine wheel, or stage of turbine wheels, that is not used to drive the compressorof 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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Term
| why do some axial flow turbine engines have more than one set of turbines and compressors? |
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Definition
| a two spool turbine engine has a low pressure and a high pressure compressor, each driven by its own turbine. The two independent systems operateat the speed at which they are more efficient. |
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Term
| what kind of bearings are used to support the rotor shaft of an aircraft turbine engine? |
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Definition
| anti friction bearings, such as ball bearings or roller bearings. |
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Term
| what is meant by a turbofan engine? |
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Definition
| an axial flow turbine engine in which the first stage of compressor blades are lenghthened, so they can force air around the outside of the gas generator portion of the engine |
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Term
| where can you find the limits of repair allowed for the compressor blades of an aircraft turbine engine? |
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Definition
| In the FAA approved service manual issued by the manufacturer of the engine. |
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Term
| 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? |
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Definition
| 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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Term
| what is meant by a hung start in a turbine engine? |
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Definition
| a start in which ignition occurs, but the engine does not accelerate to a self sustaining speed. |
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Term
| what is meant by creep of the turbine blades? |
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Definition
| a condition of permanent elongation of the turbine blades, caused by high temps and high centrifugal loading imposed on the blades |
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Term
| how is the compressor of a turbine engine cleaned? |
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Definition
| 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 cleanwater rinse. More vigorous cleaning is done by injecting a mild abrasive. |
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Term
| where is water injected into a turbine engine for cooling purposes? |
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Definition
| into the compressor inlet and into the engine diffuser case |
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Term
| at what point in a turbine engine is the temperature the highest? |
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Definition
| at the inlet to the high pressure turbine. |
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Term
| what is the function of the interconnected tubes between the cans of a turbine engine that uses can type combustors? |
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Definition
| 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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Term
| what are two types of thrust reversers that are used on turbojet engines? |
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Definition
| mechanical blockage and aerodynamic blockage. |
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Term
| what is meant by trimming a turbojet engine? |
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Definition
| adjusting the fuel control to get the correct idling and maximum thrust RPM. |
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Term
| what is meant by a hot section inspection? |
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Definition
| inspection of combustors, the turbine, and the exhaust system. |
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Term
| what is meant by on condition maintenance of a turbine engine ? |
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Definition
| monitoring of the engine performance at regular intervals and determining when maintenance is required basesd on certain operating parameters specified by the engine manufacturer. |
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Term
| what checks are required for a turbine engine preflight? |
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Definition
| cowling,air inlet,attachment points of engine to airframe,inlet guide vanes,first stage compressor or fan blades,rear turbine and exhaust system,unusual noise when compressor rotated,oil level for engine and CSDU,ck ignition system,listen for sparks. |
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Term
| what type of equipment should be used to determine that a turbine engine is performing up to the standards specified by the engine manufacturer |
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Definition
| A JetCal Analyzer/Trimmer. |
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