...Jean Thomassin; Huu Duc Vo; Njuki W. Mureithi Nonsynchronous vibration (NSV) is a particular type of aero-elastic phenomenon, where the rotor blades vibrate at nonintegral multiples of the shaft rotational frequencies. NSV behavior appears similar to off-design stall flutter but with a particular...

...M. Haake; R. Fiola; S. Staudacher A mathematical model for the prediction of the maximum speed of a high pressure turbine following a shaft failure event was developed. The model predicts the high pressure compressor and ducting system pre- and poststall behaviors such as rotating stall and surge...

... blades vibrate at nonintegral multiples of the shaft rotational frequencies in operating regimes where classical flutter is not known to occur. A physical mechanism to explain the NSV phenomenon is proposed based on the blade tip trailing edge impinging jetlike flow, and a novel theory based...

..., will be quiet relative to current turbofans. To reduce the engine weight, a system with a gearbox, or some other form of shaft speed reduction device, is proposed. This is combined with a low-speed fan and a turbine with high gap-chord spacing to further reduce turbomachinery source noise. An engine...