更多"According to the principle of four "的相关试题:
[单项选择]According to the principle of two stroke diesel engine, what is the number of its efficient work stroke per revolution?（）
A. 1/2
B. 1
C. 2
D. 3
[单项选择]For an ordinary four-stroke diesel engine the exhaust valves close （）.
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]Marine four-stroke diesel engines are mainly （）.
A. of crosshead type
B. of trunk piston type
C. of low speed type
D. all the above
[单项选择]
The working cycle of a four-stroke diesel engine consists of four events:（）
(1) compression
(2) expansion
(3) exhaust
(4) suctionThe correct sequence is
A. (4)-(2)-(3)-(1)
B. (4)-(3)-(1)-(2)
C. (4)-(3)-(2)-(1)
D. (4)-(1)-(2)-(3)
[单项选择]On a four-stroke diesel engine, when the piston is driven downwards by the expanding gas, it delivers power to the crankshaft through the （）.
A. thrust block
B. sounding rod
C. connecting rod
D. push rod
[单项选择]
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 longer
A. (1) only
B. (2) only
C. both (1) and (2)
D. neither (1) nor (2)
[单项选择]In the two stroke diesel engine, it is designed so that the oil impingement is timed to proceed only on the piston ring belt during（）
A. compression stroke
B. suction stroke
C. expansion stroke
D. exhaust stroke
[单项选择]In a four-stroke cycle diesel engine the intake valves open （）
A. before TDC and close after BDC
B. after TDC and close after BDC
C. before TDC and close before BDC
D. after TDC and close before BDC
[单项选择]Turbocharged four-stroke/cycle diesel engines utilize valve overlap for（）.
A. improving cylinder scavenging
B. preheating the combustion chamber
C. reducing air charge density
D. preventing valve wear
[单项选择]A disadvantage of a four-stroke/cycle diesel engine is （）
A. higher working temperature of piston and cylinder
B. the use of scavenge ports
C. fewer power strokes per revolution of the crankshaft
D. part of the fuel is burned as the piston is moving away from top dead center
[单项选择]If the turbocharger of a four-stroke/cycle diesel engine fails to operate, which of the following statements best describes the probable effect?（）
A. Intake manifold pressure will be high
B. Intake manifold pressure will be unaffected
C. Exhaust temperatures will be high
D. Exhaust temperatures will be low
[单项选择]The camshaft on a four-stroke/cycle diesel engine provides a means to operate the （）.
A. fuel injectors
B. exhaust valves
C. intake valves
D. all of the above
[单项选择]Scavenging in a four-stroke/cycle diesel engine occurs during the （）.
A. last part of the exhaust stroke, and the first part of the intake stroke
B. last part of the intake stroke only
C. early part of the injection stroke only
D. early part of the power stroke
[单项选择]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 gases
B. energy supplied to the turbocharger
C. air pressure to the intake manifold
D. purge of exhausted gases from the cylinders
[单项选择]In a turbocharged four-stroke/cycle diesel engine, the exhaust valve remains open until after top dead center and the intake valve opens before top dead center to（）.
A. produce a scavenging effect in the combustion space
B. equalize cylinder and exhaust manifold pressures
C. alleviate the difference in valve size between the intake and exhaust
D. flush out condensate that collects after each compression stroke
[单项选择]In a single acting, four-stroke/cycle diesel engine, the power impulse in an individual cylinder occurs （）
A. once every crankshaft revolution
B. once every two crankshaft revolutions
C. once every piston stroke
D. twice every piston stroke
[单项选择]If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because the （）.
A. cylinder compression pressure may not be high enough
B. cylinder compression temperature may be too high
C. fuel oil injection pressure may not be high enough
D. scavenge and purge process is incomplete
[单项选择]A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.
A. crankshaft revolution
B. mechanical cycle of operation
C. period of two combustion cycles
D. cycle of two events
