网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)
单选题
A disadvantage of a two-stroke/cycle diesel engine is()
A

more power strokes per revolution

B

the use of scavenge air

C

more complicated valve gear

D

higher working temperature of the piston and cylinder


参考答案

参考解析
解析: 暂无解析
更多 “单选题A disadvantage of a two-stroke/cycle diesel engine is()A more power strokes per revolutionB the use of scavenge airC more complicated valve gearD higher working temperature of the piston and cylinder” 相关考题
考题 单选题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of ()A less even torqueB higher cylinder head temperaturesC fewer power strokes per revolutionD greater weight/size requirements

考题 单选题The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speedIn maintaining this relationship, the camshaft drive causes the camshaft to rotate at()A one half crankshaft speed in a two-stroke cycle diesel engineB crankshaft speed in a two-stroke cycle diesel engineC two times crankshaft speed in a two-stroke cycle diesel engineD one-fourth times crankshaft speed in a four-stroke cycle diesel engine

考题 单选题In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the ().A starting air and fuel pumpsB piston cooling pumpsC exhaust valvesD all of the above

考题 单选题When inspecting piston rings through the ports of a two-stroke/cycle diesel engine, black areas on the sealing surfaces are the result of ()A insufficient lubricationB improper piston coolingC blow-byD overload operation

考题 单选题The size of the exhaust valve opening is ()A most critical in a four-stroke cycle diesel engineB most critical in a two-stroke/cycle diesel engineC most critical in a four-stroke/cycle diesel engine if it is turbochargedD of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine

考题 单选题Which of the two events listed occurs simultaneously in a two-stroke/cycle diesel engine?()A Exhaust and scavengingB Scavenging and compressionC Ignition and expansionD Exhaust and compression

考题 单选题In the cylinder head of a two-stroke/cycle diesel engine, valves are used for()A air intakeB a fuel outletC cooling water inletsD exhausting combustion gas

考题 单选题The exhaust system for a turbocharged two-stroke/cycle diesel engine functions to()A discharge exhaust gases and smokeB furnish energy to the turbochargerC reduce engine room noiseD all of the above

考题 单选题When would the available energy of the exhaust gases of a two-stroke/cycle diesel engine be insufficient to drive an exhaust gas turbocharger, resulting in the incorrect amount of air for combustion?()A During operation at low speedB During operation at rated speed, but low power outputC During accelerationD All of the above

考题 单选题Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because ()A bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversedB bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversedC the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engineD two-stoke/cycle diesel engines require more complicated lubrication piping

考题 单选题In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in ().A two crankshaft revolutions in a two-stroke/cycle engineB two power strokes in a two-stroke/cycle engineC one power stroke in a two-stroke/cycle engineD two piston strokes in a two-stroke/cycle engine

考题 单选题A disadvantage of a four-stroke/cycle diesel engine is ()A higher working temperature of piston and cylinderB the use of scavenge portsC fewer power strokes per revolution of the crankshaftD part of the fuel is burned as the piston is moving away from top dead center

考题 单选题Large, two-stroke/cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the ().A exhaust gas temperature systemB exhaust load systemC constant or pulse pressure systemD constant volume system

考题 单选题A large two-stroke/cycle direct reversing diesel engine is to be reversedPrior to the admission of starting air you must ()A line up the engine fore restarting with light diesel oilB reposition the fuel injection camC change the intake and exhaust valve cam positionsD place the starting cam in the intermediate position

考题 单选题Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?()A In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greaterB Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the portsC No gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engineD The gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine

考题 单选题In a two-stroke/cycle diesel engine, the exhaust gases are expelled from the cylinder by the()A exhaust manifoldB valve bridgeC pressure of the fresh air chargeD valve adjusting gear

考题 单选题If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately()A the same indicated horsepower as a four-stroke/cycle engineB twice the indicated horsepower as a four-stroke/cycle engineC one half indicated horsepower as a four-stroke/cycle engineD one power stroke for every two crankshaft revolutions

考题 单选题A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine()A has little or no internal frictionB has a lower effective compression ratioC operates with scavenge air under a positive pressureD operates without energy absorbing intake and exhaust strokes

考题 单选题The two strokes of a two-stroke/cycle diesel engine are ()A power and intakeB intake and exhaustC exhaust and compressionD compression and power

考题 单选题In a single acting, two-stroke/cycle, diesel generator engine, the power impulse in an individual cylinder occurs ()A once every crankshaft revolutionB once every two crankshaft revolutionsC once every piston strokeD twice every piston stoke

考题 单选题The process of scavenging a two-stroke/cycle diesel engine serves to()A improve fuel flow volumeB cool the exhaust valvesC reduce the intake air charge densityD increase the temperature of exhaust gases

考题 单选题The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is ().A 475 RPMB 950 RPMC 1900 RPMD 2400 RPM

考题 单选题For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because ().A it has a longer power strokeB more air gets into the cylinder each strokeC it develops twice as many power strokes at the same speedD higher combustion pressure is developed

考题 单选题A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the ().A temperature of the exhaust gasesB energy supplied to the turbochargerC air pressure to the intake manifoldD purge of exhausted gases from the cylinders

考题 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 ()A early fuel injectionB excessive bearing play within the running gearC overloading of the cylinderD all of the above

考题 单选题A six-cylinder, two-stroke/cycle diesel engine is fitted with a rotary distributing air starting systemThe speed of the rotating distributor disc is ()A one-half engine speedB the same as engine speedC twice engine speedD four times engine speed

考题 单选题A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the () (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longerA (1) onlyB (2) onlyC both (1) and (2)D neither (1) nor (2)