On the propagation of viscous wakes and potential flow in axial-turbine cascades
- Washington Univ., St. Louis, MO (United States)
This paper investigates the propagation of pressure disturbances due to potential-flow interaction and viscous-wake interaction from upstream blade rows in axial-turbine-blade rotor cascades. Results are obtained by modeling the effects of the upstream stator viscous wake and potential-flow fields as incoming disturbances on the downstream rotor flow field, where the computations are performed. A computer program is used to calculate the unsteady rotor flow fields. The amplitudes for the rotor inlet distortions due to the two types of interaction are based on a review of available experimental and computational data. The authors study the propagation of the isolated potential-flow interaction (no viscous-wake interaction), of the isolated viscous wake interaction (no potential-flow interaction), and of the combination of interactions. The discussion uses as example a lightly loaded cascade for a stator-to-rotor-pitch ratio R = 2. They examine the relative magnitudes of the unsteady forces for two different stator-exit angles. They also explain the expected differences when the stator-to-rotor pitch ratio is decreased (to R = 1) and increased (to R = 4). They offer new and previously unpublished explanations for the mechanisms of generation of unsteady forces on the rotor blades.
- OSTI ID:
- 6013950
- Journal Information:
- Journal of Turbomachinery; (United States), Journal Name: Journal of Turbomachinery; (United States) Vol. 115:1; ISSN JOTUEI; ISSN 0889-504X
- Country of Publication:
- United States
- Language:
- English
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