Investigation of Performance and Rotor Tip Flow Field in a Low Speed Research Compressor with Circumferential Groove Casing Treatment at Varying Tip Clearance

Figure 11

Spectrogram of microphone at = −0.2 (upstream rotor leading edge). (a) = 5.0% of single-stage test. (b) = 5.0% only in Rotor 3 of four-stage test.

(a)

(b)