Design optimization and CFD analysis of a oil injected twin screw compressor

The aim of this study is optimized all design parameters including parameters of rotor profile and ports of an oil injected twin screw compressor which is the most widely used among compressors with one-dimensional thermodynamic approach, simultaneously by using two different optimization techniques called RSO (Response Surface Optimization Method) and Taguchi optimization technique. The fluid volume created with the optimized rotor profile is solved in Computational Fluid Dynamics (CFD) in multiphase which including oild and air. For rotor optimization; firstly, two different rotor design approaches have been optimized with RSO (Response Surface Optimization Method). The profile that provides 1.33 % advantage in specific power between the two different optimized rotor profile obtained was taken as reference and the design parameters of this rotor were optimized via Taguchi Optimization Technique. When these two optimization techniques were compared, the profile optimized using the RSO technique with 0.34% improvement in specific power was used for port optimization and CFD (Computational Fluid Dynamic) analysis studies. In this study, the effect of rotor thread depth on comppresor performance was also investigated. The thread depth is defined by the female rotor outer diameter and the distance between axes for a fixed male rotor outer diameter. An increase of 10.34% in tread depth provided a 2.89 % improvement in the specific power. The port parameters (suction and discharge ports) was optimized by using the RSO technique and the specific power was decreased 1.17 %. The CFD analysis was performed for the optimized rotor profile and port and the results was compared with one- dimensional thermodynamic calculation. This one-dimensional thermodynamic calculations have been validated with a maximum deviation of 3.9 % provided in performance parameters according to CFD results.