0

Full Content is available to subscribers

Subscribe/Learn More  >

Experimental Investigation of a Counter-Rotating Mixed-Flow Single Stage Pump Under Cavitation Conditions

[+] Author Affiliations
Stefano Tosin, Jens Friedrichs

Technische Universität Braunschweig, Braunschweig, Germany

Andreas Dreiss

Flowserve Corporation, Hambung, Germany

Bruno Schiavello

Flowserve Corporation, Bethlehem, PA

Kariem Elebiary

Flowserve Corporation, Vernon, CA

Paper No. AJKFluids2015-33118, pp. V001T33A004; 11 pages
doi:10.1115/AJKFluids2015-33118
From:
  • ASME/JSME/KSME 2015 Joint Fluids Engineering Conference
  • Volume 1: Symposia
  • Seoul, South Korea, July 26–31, 2015
  • Conference Sponsors: Fluids Engineering Division
  • ISBN: 978-0-7918-5721-2
  • Copyright © 2015 by ASME

abstract

The increase in power per unit volume in modern pumps has been driven by manufacturing cost reduction. The first prototype of a new generation of centrifugal pumps has been experimentally and numerically investigated. It presents a particular and novel design characterized by the absence of any stator blade, which has been substituted with a counter-rotating radial impeller. According to an exhaustive literature survey, the usage of a mixed-flow impeller as a front rotor, followed by a radial-flow impeller seems to be a novel approach in pump design. The combination of a high specific speed impeller with a low specific speed counter-rotating diffuser produces flexible adaptability against varying working conditions. It also gives a rise to an increase of pressure coefficient values beyond limits of similar volute envelope. Applying the counter-rotating design principle to a radial pump increases power density, however cavitation-related issues remains a limiting factor. Counter-rotating design also features an additional degree of freedom to the system due to the independency of motor speeds of one another. This aspect improved cavitation inception characteristics especially at overload capacities. Moreover, such an arrangement required building a special test rig in order to accommodate for the double motor configuration. In this study, the NPSH3% -curve and the NPSHic cavitation inception characteristics have been measured. The system dependency on speed ratio variation has been also investigated along with the influence of the speed ration on the cavitation. Results of the cavitation inception visualizations were obtained using an endoscope at front rotor in order to analyze the behaviour of the pump under cavitation conditions. Test results showed two distinct speed ratios where maximum head and best cavitiaiton behavior were achieved. Additionally, results also confirmed that the cavitaion-free range can be optimized by using different speed ratios. A head drop-efficiency curve with variable speed ratios, which have been progressively adjusted for several flow capacities, is developed. This curve highlights the advantage of this new design compared to a conventional pump particularly under off-design conditions. It is clearly evident that delaying head deterioration, due to low inlet available suction energy, is solely attributed to the variable speed ratio of the runners.

Copyright © 2015 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In