An Evaluation of Passive Wall Treatment With Circumferential Grooves in a High-Performance Multi-Stage Axial Compressor

Abstract

Passive wall treatments with circumferential grooves in axial compressors proved to be effective in increasing the compressor stall margin in previous researches by creating a resistance to the flow that leaks in the tip clearance region of the compressor, from the rotor blade pressure side to the suction side. In the present work, a passive wall treatment with circumferential grooves was implemented in a multi-stage axial compressor. Different configurations of circumferential grooves were created at the casing of the first rotor row used in a four-stage axial flow compressor. 3D CFD flow simulations were performed in order to evaluate all the specified configurations aiming to find improvements on compressor stall margin. Investigations on the compressor flow characteristics were realized and the stall margin variations were determined. The numerical simulations were performed based on the Reynolds-Averaged Navier Stokes equations and the turbulence model was the k-ω SST. After the simulations, several rotational speeds of the compressor map characteristics, including the design-point rotational speed, were obtained for the case without casing treatment (smooth wall case) and for the case with circumferential grooves. In the results, passive wall treatment with circumferential grooves demonstrated an improvement in the compressor stall margin, especially for N = 0.60 and N = 0.90 rotational speeds.

Instability Phenomena in Centrifugal Compressors and Strategies to Extend the Operating Range: A Review

“…Finally, Chen et al [117,118] analyzed a circumferential groove casing treatment in different vaned diffusers, showing a stable range extension of 9%; in fact, this device alleviated a blockage near the diffuser, the main cause of the rotating stall in the diffuser. Additional groove solutions have been derived from studies on axial compressor configurations [119][120][121].…”

An Evaluation of Passive Wall Treatment With Circumferential Grooves at the Casing of the First and Second Blade Rotor Rows of a High-performance Multi-stage Axial Compressor

“…In recent years, some researchers have evaluated the influence of the casing treatments on the compressor stall margin for multi-stage axial compressors [20], [23], [28], [29]. Nevertheless, most applied the casing treatments only in the first blade rotor row.…”