三管轮考试48期轮机英语试卷及答案.pdf

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 .o_idated 2. The ratio of the brake horsepower to the indicated horsepower of a diesel engine is it _______ 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. 第 1 页 共 41 页 heating value 4. The greatest turbulence in a diesel engine cylinder is created by the ________ A. shape of the bustion chamber B. fuel injection spray pattern C. cylinder swept volume D. degree of peration of the fuel oil droplets 5. The projection on a shaft designed to change circular motion int up and down or back and fore motion is called ______ A. wheel B. crankshaft C. running gear 6. A clearly visible benefit of RT-fle_ engines is their ________operation at all ship speeds.This is achieved by the superior bustion performance. A. shockless 第 2 页 共 41 页 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. pared 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