Active Flow Control Concepts on a Highly Loaded Subsonic Compressor Cascade: Résumé of Experimental and Numerical Results

This paper presents experimental and numerical results for a highly loaded, low speed, linear compressor cascade with active flow control. Three active flow control concepts employing steady jets, pulsed jets, and zero mass flow jets (synthetic jets) are investigated at two different forcing locations: at the end walls and the blade suction side. Investigations are performed at the design incidence for jet-to-inlet velocity ratios of approximately 0.7 to 3.0 and two different Reynolds numbers. Detailed flow field data are collected using a five-hole pressure probe, pressure tabs on the blade surfaces, and time-resolved particle image velocimetry. Unsteady Reynolds-Averaged Navier-Stokes simulations are performed for a wide range of flow control parameters. The experimental and numerical results are used to understand the interaction between the jet and the passage flow. Variation of jet amplitude, forcing frequency and blowing angle of the different control concepts at both locations allows determination of beneficial control parameters and offers a comparison between similar control approaches. This paper combines the advantages of an expensive yet reliable experiment and a fast but limited numerical simulation. Excellent agreement in control effectiveness is found between experiment and simulation.