Suppression of Performance Curve Instability of an Axial-Flow Pump by Using a Double-Inlet-Nozzle

It has been shown that the sudden decrease of pump head in an axial flow pump caused by stall can be overcome by means of casing treatment. Flat axial grooves in front of the impeller break the swirl of the near-casing backflow. The disadvantage of this method is strong cavitation at the inlet of th...

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Bibliographic Details
Main Authors: P. Pérez Flores, G. Kosyna, D. Wulff
Format: Article
Language:English
Published: Wiley 2008-01-01
Series:International Journal of Rotating Machinery
Online Access:http://dx.doi.org/10.1155/2008/536850
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Summary:It has been shown that the sudden decrease of pump head in an axial flow pump caused by stall can be overcome by means of casing treatment. Flat axial grooves in front of the impeller break the swirl of the near-casing backflow. The disadvantage of this method is strong cavitation at the inlet of the grooves for flow rates below the stall point. In this paper another improved method to stabilize the performance curve will be presented, using a double-inlet-nozzle. At the onset of stall the initial near-casing backflow with its high swirl is lead off into the gap between both nozzles. At design conditions this double-inlet-nozzle is working as an injector, supporting the near-casing-inflow. The function of the double-inlet-nozzle is demonstrated by PIV-measurements.
ISSN:1023-621X
1542-3034