Investigation of the effect of casing circumferential groove on the performance of a contra rotating compressor

In this paper, the effect of circumferential groove-type casing treatment on improving the performance of a two-stage contra rotating axial compressor is investigated numerically. The results are presented based on numerical simulation of viscous flow in three dimensions by solving Navier-Stokes equations including continuity, momentum and energy using Ansys CFX software. Initially, in order to validate, the results are compared with the results of other researchers and a good agreement is observed. Examination of the compressor performance curve in both smooth and grooved casing indicates an increase in the stall margin in this compressor by about 8%. It is observed that the application of grooved casing in near-stall conditions reduces the occurrence of stall cells and its peripheral and axial distribution. Due to the attenuation of the tip leakage flow in the grooved shell, the interface between the main flow and the tip leakage flow moves downstream of the passage. In addition, the impact of leakage flows and shock waves, which leads to the production of large losses, is transmitted to downstream.