unit 2 Flashcards

1
Q

A jet engine derives its name from its design in that it uses

A

an exhaust-gas driven turbine wheel to drive its compressor

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2
Q

A turbo-supercharger is essentially a

A

high-capacity air pump

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3
Q

The two forces that air is subjected to after it is drawn into the guide vanes of centrifugal compressor are

A

rotational and centrifugal

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4
Q

A constructional feature of the centrifugal compressor is that the impeller

A

is forged as a single unit

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5
Q

The jet engine compressor that is cheaper to manufacture is the

A

centrifugal type, because of its fewer parts

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6
Q

Which is a constructional feature of an axial-flow compressor casing?

A

Split along the horizontal centerline

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7
Q

The percentage of combustion efficiency of a gas turbine is usually between

A

95 and 100

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8
Q

What is the most probable cause of flameout of a jet engine flying at 40,000 feet with a constant engine revolution per minute (rpm) of 50 percent?

A

the rpm is too low

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9
Q

The excess airflow that is not burned in the combustion section is used to

A

mix with and cool the burned gases

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10
Q

The inner and outer surfaces of an annular-type combustion chamber are formed by

A

interlocking stainless-steel bands

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11
Q

Fuel that accumulates after a failed start is

A

drained overboard by a drain system

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12
Q

The parts on a can-annular combustion section must be removed in a specific order because of the

A

combustion chamber crossover tubes

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13
Q

What is the most common type of fuel nozzle system?

A

Pressure-atomizing

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14
Q

Three types of turbine and van assemblies used in jet engines are impulse, reaction, and

A

reaction-impulse

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15
Q

The “fir tree” method of attaching turbine blades (buckets) to the turbine rotor disc is preferred because

A

of the temperature differential between the turbine rotor disc and the blades.

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16
Q

In an non-afterburning engine, the exhaust duct connects the turbine outlet and the

A

jet nozzle

17
Q

The purpose of the exhaust duct is to

A

straighten exhaust gas-flow

18
Q

What is one common type of variable-area orifice that is used on augmentors?

A

Segmented-flap

19
Q

The purpose of an augmentor (afterburner) in a jet engine is to

A

augment the maximum thrust capability of the basic engine

20
Q

How many different types of loads can be imposed on a jet engine bearing?

21
Q

When you handle jet engine bearings, you must change cotton gloves frequently because they

A

get soaked with sweat

22
Q

Before inspecting new jet engine bearings, you should

A

remove the preservative coating

23
Q

Next to contamination and improper lubrication, what is the greatest enemy of antifriction bearings?

A

Improper removal

24
Q

The most commonly used bearing removal tools include

A

arbor presses and bearing pullers

25
Which type of defect appears on bearings as a result of bearing parts striking together
nicks
26
Which type of defect appears on bearings as a result of small particles of foreign material becoming lodged between the rollers?
Grooves
27
Excessive bearing wear can usually be detected by
roughness of the metal
28
Before you install separable bearings, you must ensure the
bearings are a matched set
29
Of the following, the recommended method of expanding a bearing race before installation is to use a
hot-oil bath
30
The reduction gearbox on an F100-PW-220 engine reduces speed between the main fuel gear pump and the engine-driven main gearbox by
52 percent