Investigation of Unsteady Tip Clearance Flow in Axial Compressor Rotor

Abstract

Tip clearance in axial compressors is known to be detrimental to the pressure rise capability, stability and efficiency of the machine. There are two aspects of the tip clearance flow; one is blockage, which is a fluid dynamic effect, and the other is loss, which is a thermodynamic effect. Compressors often operate with tip clearances that are larger than aerodynamically desirable due to changes in tip clearance during operations and limitations in manufacturing tolerances.

In this thesis investigations are done to determine the effect of unsteady tip clearance flow in axial compressor rotor used in an industrial gas turbine. CFD analysis and Structural analysis is performed for different models by changing the tip clearance 0.5mm uniformly, non-uniform tip clearance 0.5mm & 0.68mm, 0.5mm & 0.8mm and 0.5mm & 0.9mm. CFD analysis is done by using fluid air and Structural analysis is done using materials Structural Steel, Aluminum alloy and Copper alloy. 3D modeling is done in Pro/Engineer and analysis is done in Ansys.