Slip Factor for Centrifugal Impellers Under Single and Two-Phase Flow Conditions
- 12 October 2004
- journal article
- Published by ASME International in Journal of Fluids Engineering
- Vol. 127 (2), 317-321
- https://doi.org/10.1115/1.1891153
Abstract
Throughout the history of turbomachines investigators have tried to develop reliable methods for prediction of centrifugal pump behavior. Among the parameters available to estimate the performance of this kind of machine is the slip factor. In spite of being regarded as a variable of great significance in the analysis of turbomachinery, there seem to be a misconception regarding its concept and application. Indeed, empirical correlations have been widely used to estimate the slip factor, even in the case of two-phase flow applications, where it has not been investigated. Moreover, these correlations provide a constant value of the slip factor for a given impeller only at the best efficiency point, which is an important restriction to the pump performance prediction, considering that slip factor varies with the pump flow rate. In this study, three-dimensional computational fluid dynamics simulations were carried out on an impeller of known geometry from which values of slip factor were calculated for both single- and two-phase flow (water and water-air). These results include curves of the slip factor as a function of the specific capacity and the gas-void fraction. Additionally, results for the slip factor in the case of single-phase flow (water) are given for various centrifugal impellers (, 1447, 1612, and 3513) in order to illustrate the influence of the flow rate on this parameter. Finally, based on the numerical results, a methodology for prediction of the pump head is presented. Excellent agreement with experimental results has been found. This paper attempts to contribute to a better understanding of the fluid dynamics within centrifugal pump impellers and to shed more light on the path that prediction models should follow in the future.
Keywords
This publication has 8 references indexed in Scilit:
- CFD Analysis of Electric Submersible Pumps (ESP) Handling Two-Phase MixturesJournal of Energy Resources Technology, 2004
- Prediction of Air-Water Two-Phase Flow Performance of a Centrifugal Pump Based on One-Dimensional Two-Fluid ModelJournal of Fluids Engineering, 1998
- Investigation of Centrifugal Pump Performance Under Two-Phase Flow ConditionsJournal of Fluids Engineering, 1995
- Performance of Electric Submersible Pumps in Gassy WellsSPE Production & Facilities, 1994
- An Analytical Model for Prediction of Two-Phase (Noncondensable) Flow Pump PerformanceJournal of Fluids Engineering, 1985
- Characteristics of Centrifugal Pumps Handling Air-water Mixtures and Size of Air Bubbles in Pump ImpellersBulletin of JSME, 1985
- A Review of Slip Factors for Centrifugal ImpellersJournal of Engineering for Power, 1967
- Das Förderhöhenverhältnis radialer Kreiselpumpen mit logarithmisch‐spiraligen SchaufelnZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, 1928