CFD Analysis of Tip Clearance Effects on the Performance of Transonic Axial Compressor

Abstract

Ongoing development concerning to increase engine thrust to weight ratio in a gas turbine engine which gives rises to extremely loaded compressor stages. Highly loaded compressors stability is associated with low energy tip leakage flow (TLF) which leads to the flow blockage and thermodynamic losses. This causes greater adverse effects in transonic axial flow compressors owing to the interaction of shock wave and tip leakage flow. The current paper aims for a detail investigation of tip clearances flow field region and their profound effects on aerodynamic performance, stability range and stability margin of low aspect modern transonic axial flow compressor through mathematical modeling and numerical simulation using ANSYS CFX software. Detail rotor flow field was numerically and computationally investigated at zero tip clearance, above and below of design tip clearance to conclude the performance of compressor at suitable tip clearance. A mathematical model has been established to predict the behavior of compressor rotor at choking, peak efficiency and near stall point mass flow rate conditions at different tip clearances. Mathematical model is developed to predict the behavior of compressor at different tip clearances. Furthermore, mathematical-based model results are validated with the computational results. The eminence of both model prediction and the numerical solution was assessed, and conclusions were drawn.