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Mechanical Engineering · Q17

Internal Combustion Engines (I.C. Engines)

Engineering and GATE · Mechanical Engineering · question 17

Q17

Which one of the following event would reduce volumetric efficiency of a vertical compression ignition engine?

A.
Inlet valve closing after bottom dead center
B.
Inlet valve closing before bottom dead center
Answer
C.
Inlet valve opening before top dead center
D.
Exhaust valve closing after top dead center

Answer: Option B

Solution

Answer: Option B
Solution:
Inlet valve closing before bottom dead center would reduce volumetric efficiency of a vertical compression ignition engine. -It should be quite clear that the volumetric efficiency decreases at higher rpm because the process of pushing the exhaust gases out and sucking the fresh charge inside cylinder gets lesser and lesser time.