twin-screw compressor, non-uniform clearance, normal rack
The performance of twin-screw compressors is primarily affected by the clearance between a pair of meshing rotors. This study proposes a method for calculating the normal clearance along the contact line between rotors using two normal rack curves, which are conjugated with the male and female rotors. The clearance distribution results are then compared using the HOLROYD profile management system (HPMS) software to verify their accuracy. Additionally, non-uniform clearance along the contact line between rotor surfaces is included in the compressor performance calculation to assess its influence on the flow leakage and volumetric efficiency.