The effect of tip clearance on the rotor-stator interaction and noise of marine 1.5-stage compressor

Tip-clearance (TC) noise is significant in compressors and has garnered scholarly attention for the isolated rotor. However, applying these findings to marine compressors with rotor-stator-interaction (RSI) is challenging. In this paper, a comprehensive analysis was given of a marine 1.5-stage compressor. The investigation included five different TC configurations (0, 0.25, 0.5, 0.75, and 1 mm) and the RSI was a focal point of the study. The accuracy of numerical calculations of the flow field was verified using experimental data. The results reveal a new phenomenon; the radial separation flow of the rotor's trailing edge is mixed with the TC flow and a wake above the 90 span of the blade is formed. An understanding of this mixing mechanism is crucial for model that describes the effect of TC on the RSI. The single-tone sound source of the stator's leading-edge tip area is the smallest when the TC is 0.25 mm. In contrast, the single-tone sound source is largest when the TC is equal to zero. Investigation of different TCs in three acoustic environments shows no obvious disparity in the single-tone acoustic power response of various TCs. There is, however, a correlation between the flow mixing mechanism and the noise.