To use a sector of annulus for turbomachinery flutter simulation, a time shifted phase lag (TSPL) and the Fourier series phase lag (FSPL) are implemented at the lower/upper periodic boundaries where a time shifted periodicity exits. The full annulus flutter for NASA Rotor 67 is conducted to validate the present single passage simulation with phase-lagged boundary conditions. Time accurate Reynolds averaged 3D Navier-Stokes equations are solved with a system of 5-decoupled structure modal equations in a fully coupled manner. The predicted flutter from the single passage using the TSPL shows better agreement with the full annulus than FSPL. Despite of frequency dependency, the FSPL with fewer order harmonics are sufficient for turbomachinery flutter simulation.
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