Effect of Rotor Tip Gap Variation at the Rear Stages of an Axial Flow Compressor

Abstract

In this paper, detailed analysis of the tip flow of an axial compressor rotor blade has been carried out using the commercial CFD package ANSYS CFX. The rotor blade was designed such that it is reminiscent of the rear stages of a multi-stage axial compressor. The effects of varying tip gaps are studied using CFD simulations for overall pressure rise and flow physics of the tip flow at the design point and near the peak pressure point. Rig tests of a low speed research compressor rotor with 3% tip clearance provided characteristics plots for validation of the CFD results. With increase in clearance from 1% to 4%, the rotor pressure rise at the design point was observed to decrease linearly. Increase in the clearance increases the cross flow across the tip; however, the magnitude of the average jet velocity crossing the tip decreases. The tip leakage vortex was observed to stay close to the suction surface with increase in clearance.

Numerical study on the effect of blade tip clearance change on stall margin of the transonic axial flow compressor rotor

“…A lot of research results have found that the TLF is an extremely complex three-dimensional viscous flow, which is importantly related to the internal flow loss and stall of the compressor. [1][2][3][4][5] Therefore, in order to further improve the performance of the compressor, it is of great significance to carry out research on the effect of the BTC on the performance of the compressor.…”