CFD Analysis of Screw Compressor

Abstract

The twin-screw compressor is a positive displacement machine used for compressing gases to moderate pressures. It comprises of a pair of inter-meshing rotors with helical grooves machined on them, contained in a casing which fit closely around them. The rotors and casing are separated by very small clearances. They may operate without internal lubrication, oil injected or with other fluids injected during the compression process. The present work is aimed to study physics of the screw compressor and its performances using CFD modeling. SCORG (Screw Compressor Rotor Grid Generator) is specialized software specially designed to generate grid of fluid domain is used in this study. Simulations were carried out using ANSYS CFX. Result shows good agreement with experimental results which are presented in the literature [1]. Effect of three different speeds on performance of screw compressor has been studied keeping other parameter constant. It is found that with the increase of speed there is increase in discharge pressure, power consumption, adiabatic efficiency and volumetric efficiency but decrease in discharge temperature.