47期轮机英语考试题.doc

47期轮机英语考试题目 一单项选择题 .The___ engine is used for alternators and some times for main propulsion provide a propeller of between 90 to 120 rpm. A.four-stroke B.two-stroke. C.slow speed D.reversible B2.The abbreviation”MIP”stands for____, A.middle indicating pressure B.mean indicated pressure C.mean pitch D.middle indicated power D3.The cetane number of a diesel fuel oil indicates its____. A.viscosity B.acid content C.heating value D.ignition quality C4.In a two-stroke engine the camshaft rotates at___the enging rotational speed. A.half B.twice C.the same speed as D.four times D5.A diesel enging is similar to a gasoline engine except that the former has no ____. A.cross-head B.cylinder C.connecting rod D.spark plug C6.It is easier to replace a dry cylinder liner than a wet one because____. A.of the thin wall thickedss B.honing makes it easier to maintain the desired oil film C.water seals are not required D.it fits more loosely due to a decrease in heat transfer through the composite wall D7.A main bearing consists of two shells which are secured by means of studs and____. A.tie rods B.though bolts C.lead wires D.bearing caps C8.However fast or slow the combustion rate,it is still a____between carbon,hydrogen,sulph and oxygen that releases heat. A.physical deformation B.state exchange C.chemical reaction D.coalescence A9.During the fuel injection period,fuel pressure must exceed cylinder gas pressure to____. A.ensure penetration and distribution of the fuel in the combustion chamber B.ensure the needle valves is flushed clean duringeach injection C.prevent combustion gas blowback into the open needle valve Dprevent reflected pressure waves when the neddle valve close. B10.In a diesel engine lube oil system ,which of the following parts should be lubricated first? A.Camshaft bearings B.Main bearings C.Piston crowns D.Cylinder walls B11.In a diesel