Study of the control over the clearance leakage flow by modeling a non-axisymmetrical wheel hub of an axial flow compressor

A full three-dimensional numerical simulation was performed of a single-stage axial flow compressor with a clearance between the stator and rotor. An analysis of the flow field indicates that the leakage flow from the clearance between the stator and rotor can result in a relatively large flow separation in the end wall zone of the passage. To control the flow loss, a non-axisymmetrical modeling was performed of the wheel hub of the stator and the overall performance of the compressor was improved after the said modeling. The flow field analytic results show that the non-axisymmetrical end wall modeling can change the distribution of the static pressure on the end wall, thus improving the flow pattern of the clearance leakage flow in the passage and eliminating the return flow loss zone at the outlet of the passage. As a result, the total pressure ratio of the compressor increases and the isentropic efficiency goes up by 0.9%.