第45期轮机英语

第45期轮机英语

A1. These acid residues must be prevented from entering the crankcase otherwise the lube oil would be _______

A. contaminated B .emulsified C deteriorated D .oxidated

B2. 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

D3. The cetane number of a diesel fuel oil medicates its _________

A. viscosity

B. acid content

C. heating value

D. ignition quality

D4. 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 D5. 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

D. cam

B6. 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

D7. 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

B8. 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

A9. ________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

B10. 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

D11. 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

C12. 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

C13. 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