Question

with increasing of clearance volume the volumetric efficiency of a reciprocating compressor

Answer 1

Clearance volume is the volume of the cylinder that is not swept by the piston.

Clearance is provided so that the piston from ramming the cylinder head thus physical damage.

If the clearance volume increases, the compression ratio of the cylinder will decrease and this will result in lesser potential energy stored in the compressor.

If the clearance volume decreases, then the compression ratio will increase thus resulting in physical damage to the cylinder.