once every crankshaft revolution
once every two crankshaft revolutions
once every piston stroke
twice every piston stroke
第1题:
supercharging
scavenging
turbulence
swept volume charging
第2题:
The direction of pressure on the journal in four-stroke engine is continuously
positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
Low-stroke engines usually consume less lube oil than four-stroke engines
第3题:
during the valve overlap period
with only the exhaust valve open
at a pressure below atmospheric
without cooling the cylinders or pistons
第4题:
the same indicated horsepower as a four-stroke/cycle engine
twice the indicated horsepower as a four-stroke/cycle engine
one half indicated horsepower as a four-stroke/cycle engine
one power stroke for every two crankshaft revolutions
第5题:
reduce engine horsepower output
aid in silencing the exhaust noise
increase the mean effective pressure
contribute to effective cylinder scavenging
第6题:
engine speed
kilowatt load
fuel injection pressure
air intake manifold temperature
第7题:
Intake stroke
Compression stroke
Exhaust stroke
Pumping stroke
第8题:
intake stroke
exhaust stroke
power stroke
compression stroke
第9题:
on the power stroke
on the exhaust stroke
at the end of the power stroke
at the start of the intake stroke
第10题:
fuel injectors
exhaust valves
intake valves
all of the above
第11题:
crankshaft revolution
mechanical cycle of operation
period of two combustion cycles
cycle of two events
第12题:
most critical in a four-stroke cycle diesel engine
most critical in a two-stroke/cycle diesel engine
most critical in a four-stroke/cycle diesel engine if it is turbocharged
of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
第13题:
bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversed
bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversed
the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine
two-stoke/cycle diesel engines require more complicated lubrication piping
第14题:
In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greater
Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the ports
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 engine
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
第15题:
piston skirt
pinion
crosshead
compression rings
第16题:
has little or no internal friction
has a lower effective compression ratio
operates with scavenge air under a positive pressure
operates without energy absorbing intake and exhaust strokes
第17题:
525 RPM
775 RPM
1550 RPM
1800 RPM
第18题:
once every crankshaft revolution
once every two crankshaft revolutions
once every piston stroke
twice every piston stoke
第19题:
it has a longer power stroke
more air gets into the cylinder each stroke
it develops twice as many power strokes at the same speed
higher combustion pressure is developed
第20题:
temperature of the exhaust gases
energy supplied to the turbocharger
air pressure to the intake manifold
purge of exhausted gases from the cylinders
第21题:
(1) only
(2) only
both (1) and (2)
neither (1) nor (2)