三管轮考试48期轮机英语试卷及答案

轮机英语第45期

1.These acid residues must be prevented from entering the crankcase otherwise the lube oil

would be _______

A. contaminated B .emulsified C deteriorated D .oxidated

2. The ratio of the brake horsepower to the indicated horsepower of a diesel engine is its

_______

A. thermal efficiency

B. mechanical efficiency

C. brake thermal efficiency

D. volumetric efficiency

3. The cetane number of a diesel fuel oil medicates its _________

A. viscosity

B. acid content

C. heating value

4. The greatest turbulence in a diesel engine cylinder is created by the ________

A. shape of the combustion chamber

B. fuel injection spray pattern

C. cylinder swept volume

D. degree of penetration of the fuel oil droplets

5. The projection on a shaft designed to change circular motion into up and down or back and

fore motion is called ______

A. wheel

B. crankshaft

C. running gear

6. A clearly visible benefit of RT-flex engines is their ________operation at all ship speeds.This

is achieved by the superior combustion performance.

A. shockless

B. smokeless

C. no vibration D noiseless

7. A main bearing consists of two shells which are secured by means of studs and______

A. tie rods

B. through bolts

C. lead wires

D. bearing caps

8. Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage

of _________

A. less even torque

B. higher cylinder head temperatures

C. fewer power strokes per revolution

D. greater weight/size requirements

9. ________controls the fuel oil temperature in order to provide oil at the correct viscosity for

combustion

A. The viscosity regulator

B. The temperature controller

C. The flow meter

D. The pressure switch

10. A lubricant often has to perform many duties in any situation, in addition to its fundamental

job of __________

A. resisting oxidization

B. reducing friction

C. promoting moving speed

D. developing inertia

11. Shaker, circulation, and spray are the three general methods used in _______

A. pre-injection fuel oil treatment

B. lube oil filtration

C. lube oil purification

D. piston cooling

12. Which of the diesel engine components listed increases air density and helps to improve

engine operating efficiency?

A. Impeller

B. Air bottle

C. Air cooler D Exhaust diffuser

13. Each cylinder has one starting valve which is usually opened by air pressure and closed by

__________.

A. nuts and bolts

B. new joints

C. spring force

D. sealing rings