Hydrodynamic Impeller Stiffness, Damping, and Inertia in the Rotordynamics of Centrifugal Flow Pumps
CaltechAUTHORS
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Title 
Hydrodynamic Impeller Stiffness, Damping, and Inertia in the Rotordynamics of Centrifugal Flow Pumps


Creator 
Jery, B.
Acosta, A. J. Brennen, C. E. Caughey, T. K. 

Subject 
Caltech Library Services


Description 
Measurements were made of the lateral hydrodynamic forces experienced by a centrifugal pump impeller performing circular whirl motions within several volute geometries. Experiments were conducted for various flow coefficients, [phi], impeller rotating speeds or angular frequencies, w, and the angular frequency of the whirl motion, [omega], was varied from zero to nearly synchronous (equation) and to nearly antisynchronous (equation). The lateral forces were decomposed into (i) time averaged lateral forces and (ii) hydrodynamic force matrices representing the variation of the lateral forces with position of the impeller center. No assumptions concerning the form of these matrices need to be made. The latter can be further decomposed according to the variation with whirl frequency, the result being "stiffness", "damping", and "fluid inertial" rotordynamic force matrices. It was found that these force matrices essentially consist of equal diagonal terms and skewsymmetric offdiagonal terms. One consequence of this is that during its whirl motion the impeller experiences forces acting normal and tangential to the locus of whirl. Data on these normal and tangential forces are presented; in particular it is shown that there exists a region of positive reduced whirl frequencies, [omega/w], within which the hydrodynamic forces can be destabilizing with respect to whirl.


Publisher 
National Aeronautics and Space Administration


Date 
198405


Type 
Book Section
PeerReviewed 

Format 
application/pdf


Identifier 
http://authors.library.caltech.edu/214/1/JER062.pdf
Jery, B. and Acosta, A. J. and Brennen, C. E. and Caughey, T. K. (1984) Hydrodynamic Impeller Stiffness, Damping, and Inertia in the Rotordynamics of Centrifugal Flow Pumps. In: Rotordynamic instability problems in highperformance turbomachinery: proceedings of a workshop held at Texas A&M University, May 2830, 1984. NASA Conference Publication. No.CP2338. National Aeronautics and Space Administration , Washington, DC, USA, pp. 137160. http://resolver.caltech.edu/CaltechAUTHORS:JERriphpt84 <http://resolver.caltech.edu/CaltechAUTHORS:JERriphpt84> 

Relation 
http://resolver.caltech.edu/CaltechAUTHORS:JERriphpt84
http://authors.library.caltech.edu/214/ 
