NTRS - NASA Technical Reports Server

Back to Results
Two-dimensional unsteady analysis of fluid forces on a whirling centrifugal impeller in a voluteDestabilizing fluid forces on a whirling centrifugal impeller rotating in a volute were observed. A quasisteady analysis neglecting shed vorticity or an unsteady analysis without a volute does not predict the existence of such destabilizing fluid forces on a whirling impeller. The effects of a volute and the shed vorticity are considered. We treat cases when an impeller with an infinite number of vanes rotates with a constant velocity omega and its center whirls with a constant eccentric radius epsilon and a constant whirling velocity psi. It is assumed that: (1) the number of the vanes is so large that the impeller can be treated as an actuator impeller in which the flow is perfectly guided; (2) flow is inviscid, incompressible and two dimensional; (3) the eccentricity epsilon is so small that unsteady components can be linearized; (4) vorticity is transported on a prescribed mean flow, the operating point is near design flow rate; and (5) the volute can be represented by a curved plate.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Tsujimoto, Y.
(Osaka Univ. Osaka, Japan)
Acosta, A. J.
(California Inst. of Tech. Pasadena, United States)
Brennen, C. E.
(California Inst. of Tech. Pasadena, United States)
Date Acquired
August 12, 2013
Publication Date
December 1, 1984
Publication Information
Publication: NASA. Lewis Research Center Rotordynamic Instability Problems in High-Performance Turbomachinery
Subject Category
Mechanical Engineering
Accession Number
Distribution Limits
Work of the US Gov. Public Use Permitted.
No Preview Available