Numerical Simulation of Tip Leakage Flow Structure in the Transonic Axial Compressor in Different Performance Conditions

In this paper tip leakage flow structure of a transonic axial compressor rotor in different performance conditions will be simulated. Results have been presented according to a 3D numerical simulation of the viscous flow and solving Navier-Stokes, Continuity and energy equations using Ansys- CFX software. Initially, performance curves have been derived and compared with experimental results and have shown good agreement. Then, results have been obtained from three mass flow rates including design, choke and near stall conditions. The results have indicated that reduction of mass flow rate from chock to stall condition leads to increase in the tip leakage flow strength. This phenomena causes to more loss, especially in the blade tip region. In addition, position of shock line moves to upstream when the mass flow rate decreases. The tip leakage flow, shock and main flow contact cause a complicated flow structure near stall condition which leads to increase in entropy, vortex flow and blockage.