Performance enhancement of an axial flow compressor using active flow control technique

Abstract

This research article focuses on improving the efficiency of an axial flow compressor stage, enhancing the stall margin, and optimizing flow parameters. Utilizing the NACA 65 series rotor airfoil with 12 blades, the study employs numerical simulations using the K-epsilon turbulence model. The model is validated with experimental data under specific boundary conditions, including a total pressure at the intake and a static pressure at the exit, initially set at atmospheric pressure. The outlet static pressure is incrementally increased until the rotor reaches stall. At this stall point, the tip injection method, a well-known active flow control technique, is implemented to mitigate flow instabilities. Injectors are placed at the leading edge of the rotor blades, distributed circumferentially. The tip injection parameters include 0.3% of the total mass flow rate, a pitch angle of 30 degrees and yaw angles ranging from −15 to +15 degrees. The analysis shows a stall margin improvement (SMI) of 14.26% with the 0.3% total mass flow rate injection. A decrease in the yaw angle reduces blockage and promotes smoother flow over the rotor blade, with the optimal stall margin enhancement occurring at an adverse yaw angle of −15 degrees. This study demonstrates significant SMI in the axial flow compressor rotor using specific active flow control parameters, particularly highlighting the critical role of adverse yaw angles in the tip injection method in enhancing stall margin, contributing to overall efficiency and stability.

Keywords

• NACA
• CFD
• ANSYS-CFX
• axial flow compressor
• stall margin improvement
• tip injection