Trunk-type diesel engine pistons are most effectively cooled by heat（）

A . prolonged maintenance intervals B . improved atomization C . greater fuel economy D . incomplete combustio

A . governor malfunctions B . fuel injection system malfunctions C . high cylinder lube oil temperatures D . low intake temperature

A . low oil pressure B . high coolant pressure C . leaking fuel injector D . cracked cylinder head or liner

A . ignition lag B . engine horsepower C . lube oil system pressure D . specific fuel consumptio

A . has little or no internal friction B . has a lower effective compression ratio C . operates with scavenge air under a positive pressure D . operates without energy absorbing intake and exhaust stroke

A . open the bypass line B . cut in the lube oil cooler C . pressurize the lube oil system D . top off the expansion tank

A . runs out of fuel B . has low lubricating oil pressure C . exceeds a set maximum speed D . has high cooling water temperature

A . they are more heavily built B . the fuel used is less volatile C . they can be easily reversed D . they operate at a lower speed

A . crankcase pressure B . lube oil pressure C . saltwater pressure D . exhaust temperature

A . blows out the exhaust gases B . supplies oxygen for combustion C . cools the valves and cylinder walls D . all of the above

A . piston skirt B . pinion C . crosshead D . compression ring

A . delivering more air into the cylinder than it would normally receive during an ordinary charging process B . forcing the products of combustion out of the cylinder with the fresh air charge C . collecting the air charge at the cleaner D . combustion and expansion of hot ga

A . reducing exhaust gas velocity B . increasing the frequency of gas vibration C . the use of long head pipes D . the use of zinc electrode

A、A. turbine engine B、B. gas turbine C、C. steam engine D、D. internal combustion engine

A . opposed to the crankshaft rocking couple B . resonant with the crankshaft natural frequency C . critical fore and aft crankshaft vibrations D . horizontal whipping motions of the crankshaft

A . four cycle B . compression ignition C . vacuum ignition D . external combustio

A . cylinders B . exhaust valves C . pistons D . fuel valve

A . failing to reach rated speed B . knocking under maximum load C . hunting or surging under light load D . overspeeding and running away

A . slam charger B . turbocharger C . fuel atomizer D . fuel injector

A . injecting fuel oil into a cylinder B . removing exhaust gases from the cylinder C . forcing air into the cylinders under pressure after the exhaust valve has dosed D . a combination of all the above

A . passing the exhaust through long head pipes B . diffusing exhaust vibrations through activated carbon baffles C . increasing the exhaust gas velocity D . reducing the exhaust gas velocity

A . increase exhaust back pressure B . causes excessive crankcase pressure C . can only be detected by a compression check D . decreases fuel consumptio

A.piston skirt B.pinion C.crosshead D.compression rings

A.principle B.principal C.cause D.case