1. The stator assembly includes 18 vanes for which symmetrical NACA 0010-35 airfoil sections were used. Chord length is 50 mm all over the span. The vanes have no lean, twist or sweep and have zero incidence angle with respect to the axial direction. Separation between rotor plane and leading edge of the stator vanes was 15 mm.
2. N -1910 RPM The number of e-stations (N ) was 64 for the detailed 6-traverse (-31 S m d 38) and 16 for the limited traverse (-7 5 m 5 7)
3. Among the rotor speeds tested the lowest one of 1910 RPM is a special case since the Tyler & Sofrin interaction modes according to m = nB - kV are cut-off up to the 4th BPF harmonic. Figure 4 shows m spectra. The cut-on range is indicated in the mode spectra by a the bar along the horizontal axis. Also indicated are T & S modes with magnitude above 10 Pa. At the 5th harmonic the m = 8 mode is right at its cut-on point and dominates the mode spectrum.
4. radial station r (r = 176 mm). N = 1910 AP8, N O= 64