Transient Analysis of Flow Unsteadiness and Noise Characteristics in a Centrifugal Compressor with a Novel Vaned Diffuser

The demands to apply transonic centrifugal compressor have increased in the advanced gas turbine engines. Various techniques are used increase aerodynamic performance of compressor. effects inclined leading edges diffuser vanes a on flow-field unsteadiness and noise generation investigated by solving compressible, three-dimensional, transient Navier–Stokes equations. Diffuser with various inclination angles edge from shroud-to-hub hub-to-shroud numerically modeled. results show that improves (2.6%), proper angle is effective stall margin (3.88%). In addition, this study, pressure variations radiated prediction at design operating point emphasized. influences waves were captured time/space domain different convective velocities. fluctuation spectra calculated investigate tonal blade passing frequency (BPF) noise, it shown applied blades effective, not only improve margin, but also reduce BPF (7.6 dB sound level reduction). Moreover, found could suppress separation regions eddy structures inside passages diffuser, which reduction overall broadband