reduce air charge turbulence
induce air swirl
deflect hot combustion gas away from the valves
oppose the effects of piston induced squish
第1题：
Which lubricating oil additive is used in diesel engines to reduce the tendency(倾向)for sludge and varnish to form on the engine parts?
A.Flash point improvers
B.Pour point improvers
C.Inhibitors
D.Foam suppressors(抑制物)
第2题：
Which device is used in wireless networks to send transmissions to a target area?（）
第3题：
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.
A.The direction of pressure on the journal in four-stroke engine is continuously
B.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
C.four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
D.Low-stroke engines usually consume less lube oil than four-stroke engines
第4题：
wide compression rings are used
oil rings are located above the piston
chromium plating is used on all piston rings
oil rings are located near the bottom of the piston skirt
第5题：
Slow speed diesel engines
Medium-speed diesel engines
Steam engines
Gasoline engines
第6题：
A Kort nozzle is a(n) ______.
A.hollow tube surrounding the propeller used to improve thrust
B.nozzle attached to a firefighting hose
C.intake valve on a diesel engine
D.piston cylinder on a diesel engine
第7题：
the extra weight required for the diesel reduction gearing
a minimum speed for the engines that limits the minimum speed of the vessel
the higher fuel consumption per SHP
the low efficiency of the system when a controllable pitch propeller is used
第8题：
Diesel engines driving alternators operating in parallel must maintain a set frequency regardless of load changes. The governor characteristic used to accomplish this is known as _______.
A.actuation
B.sensitivity
C.compensation
D.promptness
第9题：
Ⅰonly
Ⅱonly
bothⅠand Ⅱ
neitherⅠnor Ⅱ
第10题：
fuel oil vapor at the sludge tank vent
unburned fuel vapors in the scavenge air receiver
lube oil vapors in the crank case
lube oil vapors in the engine room