Foam-Metal Casing Treatment on an Axial Flow Compressor: Stability Improvement and Noise Reduction

A set of foam metal casing treatment (FMCT) has been investigated to assess the stability improvement and noise reduction on an axial compressor. Three FMCTs with different PPI (Pores Per Inch), 20, 35, and 50, are tested experimentally. Two installation locations of foam metal in the casing are also considered and investigated. At location 1, it is found that the FMCT improves the stall margin by 5.4–8.7%, and the attenuation of compressor noise is up to 5 dB. At location 2, the stall margin is extended by 22.2–37.1% but increasing the noise mostly. Besides, foam metal at location 1 causes less efficiency loss than that at location 2. Based on the analysis in near-casing pressure distribution, spanwise performance comparison, and stall process, the mechanism of the FMCT for enhancing the compressor stability is also discussed.