Air Compressor Volumetric Efficiency

Volumetric efficiency = Free air delivered m3/min / Compressor displacement 

Compressor Displacement = Π/4 x D2 x L x N x S x n

Where,
D = Cylinder bore, meter; 
L = Cylinder stroke, meter; 
N = Compressor speed rpm; 

S = 1 for single acting and 2 for double acting cylinders; 
n = No. of cylinders