【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 greater
B.
Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the ports
C.
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
D.
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
【单选题】The average exhaust temperature of a two-stroke/cycle diesel engine with a turbine-driven supercharger is lower than a similar four-stroke/cycle engine at equal loads because____.
A.
two-stroke/cycle diesel engines have a higher MEP than four-stroke/cycle diesel engine
B.
four-stroke/cycle diesel engine exhaust is cooled by scavenging air
C.
two-stroke/cycle diesel engines have a lower MEP than four-stroke/cycle diesel engines
D.
the opening of the two-stroke/cycle diesel exhaust ports or valves occurs much later than in four-stroke /cycle diesel engine
【单选题】The average exhaust temperature of a two-stroke/cycle diesel engine with a turbine-driven supercharger is lower than a similar four-stroke/cycle diesel engine at equal loads because ____.
A.
two-stroke/cycle diesel engines have a higher M.E.P than four-stroke/cycle diesel engines
B.
four-stroke/cycle diesel engine exhaust is cooled by scavenging air
C.
two-stroke/cycle diesel engines have a lower M.E.P_than four-stroke/cycle diesel engines
D.
the opening of the two-stroke/cycle diesel exhaust ports or valves occurs much later than in four-stroke/cycle diesel engines
【简答题】Cloze test. As we all know, Chinese handwriting has infinite power to express differences of character and cultivation. But we have to admit that traditional handwriting has become a 1 art, now that k...
【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 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 strokes