单选题Worn main bearing will cause the compression ratio of an auxiliary diesel engine to()AincreaseBdecreaseCremain the sameDincrease on compression decrease on expansion

单选题
Worn main bearing will cause the compression ratio of an auxiliary diesel engine to()
A

increase

B

decrease

C

remain the same

D

increase on compression decrease on expansion


参考解析

解析: 暂无解析

相关考题:

If a firm has a quick ratio of 1, the subsequent payment of an account payable will cause the ratio to increase.() 此题为判断题(对,错)。

Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?A.compression must be low for effective spark ignitionB.compression must be low for required horsepower and torque generationC.compression must be low to prevent pre-ignitionD.compression must be low to have effective pre-ignition

Low compression in a diesel engine could be caused byA.worn or broken cylinder liner sealing ringsB.high cooling water temperatureC.worn or broken piston ringsD.low fuel oil pressure

If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably _____.A.misalignment or worn main bearingsB.insufficient cylinder lubricationC.defective or poorly fitted valvesD.All of the above

音频出入的MAIN口和AUX口说法正确的是() A.MAIN口和AUX口都没有回声抵消功能B.Main接口有回声抵消功能,听不到自己的声音C.Aux接口没有回声抵消功能,可以听见自己的声音D.两个接口都有回声体抵消功能

Adjust ______by means of lead wire.A.the clearance of the main bearingB.the diameter of main bearingC.the gap of main bearingD.the tolerance of main bearing

材料:Spark erosion is caused by a voltage discharge between the main bearing and journal surface. The cause of the potential is the development of a galvanic element between the ship’s hull, sea water, and the propeller shaft/crankshaft.The oil film acts as a dielectric. The puncture voltage in the bearing depends on the thickness of the oil film. With increasing engine ratings, the specific load in the main bearing is increased. his will reduce the oil film thickness, and enable the discharge to take place at a lower voltage level.Since the hydrodynamic oil film thickness varies through a rotation cycle, the discharge will take place at roughly the same instant during each rotation cycle, i.e. when the film thickness is at its minimum. The roughening will accordingly be concentrated in certain areas on the journal surface. In the early stages, the roughened areas can resemble pitting erosion. but later, as the roughness increases, the small craters will scrape off and pick up white metal-hence the silvery white appearance.Therefore, to ensure protection against spark erosion, the potential level must be kept at maximum 80 mV, which is feasible today with a high efficiency earthing device. If an earthing device is installed, its effectiveness must be checked regularly. Spark erosion is only observed in main bearings and main bearing journals.问题:According to the paragraph one, a voltage between the main bearing and journal surface is produced by______.A.propeller rotationB.leakage from M/E electric control unitC.a galvanic elementD.friction between the main bearing and journal surface______engine ratings increase, the hydrodynamic oil film between the main bearing and journal surface is______.A.The lower/thinnerB.The higher/the thickerC.The lower/thickerD.The higher/thinnerWhen will the spark erosion take place on the journal surface during each rotation cycle?A.when the film thickness is at its minimumB.when the film thickness is at its maximumC.when the engine is on its compression strokeD.when the engine is on its exhaust strokeDuring the engine room watch keeping, which equipment must be noted to ensure protection against spark erosion?A.the antifouling plantB.the earthing deviceC.the main engine electric heating coilsD.the shaft generator请帮忙给出每个问题的正确答案和分析,谢谢!

A wobbling tail shaft is an indication of ______.A.shallow waterB.an engine that is misfiringC.a tight tail shaft glandD.worn stern bearing or misalignment

Which of these terms refers to call issues that cause variations in timing or time of arrival?()A、queuingB、jitterC、packet lossD、digitized samplingE、signal-to-noise ratio ratio

音频出入的MAIN口和AUX口说法正确的是()A、MAIN口和AUX口都没有回声抵消功能B、Main接口有回声抵消功能,听不到自己的声音C、Aux接口没有回声抵消功能,可以听见自己的声音D、两个接口都有回声体抵消功能

单选题Worn main bearings in a diesel engine can result in ()Adecreased compression pressureBincreased lube oil pressureClower lube oil temperatureDexcessive leakage past the piston rings

单选题Adjust () by means of lead wire.Athe clearance of the main bearingBthe diameter of main bearingCthe gap of main beatingDthe tolerance of main bearing

单选题Which of the listed bearing types is an example of a solid bearing?()APiston wrist pin bushingBturbine bearingCSpring bearingDDiesel engine main bearing

单选题Which of the following operating conditions can occur when shims are removed from the joint between the foot of a marine type diesel engine connecting rod and the bearing box?()ADecreased connecting rod bearing clearanceBIncreased connecting rod bearing clearanceCDecreased compression ratioDIncreased compression ratio

单选题Low compression of diesel engine may result from ()Aa worn cylinderBbroken piston ringsCany of A and BDnone of the above

单选题If the compression ratio is increased on any diesel engine, ()Athe expansion ratio will decreaseBcombustion will be slowed downCthermal efficiency will decreaseDthermal efficiency will increase

单选题A distance piece, with ground faces, may be interposed between the rod and the bearing housing, its thickness being chosen to ensure the correct ().Aexpansion ratioBpressure ratioCcompression ratioDclearance ratio

单选题For a given fuel, a change in the compression ratio will affect the ignition lag by which of the listed means?()AAn increase in compression ratio will increase the ignition lagBAn increase in compression ratio will decrease the ignition lagCA decrease in compression ratio will decrease the ignition lagDA decrease in ignition lag will increase the compression ratio

单选题Measure () by means of lead wire.Athe clearance of the main bearingBthe play of the miler bearingCthe gap of the main bearingDthe tolerance of the main bearing

单选题Low compression results from ().Aa worn cylinderBbroken piston ringsCeither A or BDnone of the above

单选题If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably ().Amisalignment or worn main bearingsBinsufficient cylinder lubricationCdefective or poorly fitted valvesDall of the above

单选题The insertion of shims between the foot of a marine type connecting rod and a bearing box would result in ()Aincreased compression ratioBdecreased compression ratioCincreased bearing clearanceDdecreased bearing clearance

单选题To determine the main bearing clearance of a propulsion diesel engine, you should measure the main bearing shell using a ball anvil outside micrometer and measure the crankshaft journal using a/an ()AtelescopingBring ‘snap’ gaugeCinside vernier caliperDoutside micrometer

单选题Which of the following relationships should occur between the temperature developed in a combustion space, and the compression ratio of the engine?()AHigher compression ratios create higher temperatureBHigher temperatures create higher compression ratiosClow temperatures create higher compression ratiosDHigher compression ratios create low temperatures

单选题If a diesel engines exhaust temperature is abnormally high, the cause could be()Atoo light of a loadBinjection timing is too earlyCoverloading of the engineDtoo low of a compression ratio

单选题Higher than normal temperature air passing through the intake of a diesel engine will result in()Agreater overall efficiencyBgreater fuel economyClower horsepowerDlower compression ratio

单选题A possible cause for an individual piston to knock when at TDC on a slow-speed, two-stroke/cycle main propulsion diesel engine could be due to ()Aearly fuel injectionBexcessive bearing play within the running gearCoverloading of the cylinderDall of the above