Question 43General Subjects - Assistant Engineer

The correct answer is A) heating of the air leaving the cylinders. In a low-pressure air compressor, the loss of volumetric efficiency is primarily due to the heating of the air as it leaves the cylinders. This heating causes the air to expand, reducing the amount of air that can be drawn into the cylinders on the next intake stroke, resulting in a decrease in volumetric efficiency. The other options are incorrect because: B) constant enlargement of the clearance expansion volume is not a typical cause of volumetric efficiency loss in low-pressure air compressors, C) adiabatic compression in the intercooler is not a factor in volumetric efficiency, and D) inaccurate valve timing would affect the overall compressor performance, but not specifically the volumetric efficiency.