Investigation of the Motion of Bubbles in a Centrifugal Pump Impeller

Stel, Henrique; Ofuchi, Edgar M.; Sabino, Renzo Harkov Gutierrez; Ancajima, Felipe C.; Bertoldi, Dalton; Neto, Moisés A. Marcelino; Morales, Rigoberto E. M.

doi:10.1115/1.4041230

Cited by 30 publications

(15 citation statements)

References 25 publications

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“…Sato et al [10] performed visualizations for various impeller blade angles. More recently, Stel et al [11] investigated the bubbles using a high speed camera to track the bubble motion, allowing for an understanding of coalescence effects. Mansour et al [12] performed an experimental analysis on both an open and closed 2D impeller pump aiming to more precisely define pump surge and break-down locations.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

Zhang

Bois

et al. 2019

Energies

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Centrifugal pumps are widely used and are known to be sensitive to inlet air-water two-phase flow conditions. The pump performance degradation mainly depends on the changes in the two-phase flow behavior inside the pump. In the present paper, experimental overall pump performance tests were performed for two different rotational speeds and several inlet air void fractions (αi) up to pump shut-off condition. Visualizations were also performed on the flow patterns of a whole impeller passage and the volute tongue area to physically understand pump performance degradation. The results showed that liquid flow modification does not follow head modification as described by affinity laws, which are only valid for homogeneous bubbly flow regimes. Three-dimensional effects were more pronounced when inlet void fraction increased up to 3%. Bubbly flow with low mean velocities were observed close to the volute tongue for all αi, and returned back to the impeller blade passages. The starting point of pump break down was related to a strong inward reverse flow that occurred in the vicinity of the shroud gap between the impeller and volute tongue area.

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Section: Introductionmentioning

confidence: 99%

Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

Zhang

Bois

et al. 2019

Energies

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“…An evaluation of local void fraction in two phase flows recently obtained by Schäfer et al [11], using the X-ray tomography technique, also detected a thin gas film on the pressure side for the first time. In addition, Stel [12] proposed a force analysis in order to track single bubble trajectories, based on a Lagrangian approach, including bubble size effects. This analysis, however, does not take into account bubble interactions.…”

Section: Introductionmentioning

confidence: 99%

A Review of Design Considerations of Centrifugal Pump Capability for Handling Inlet Gas-Liquid Two-Phase Flows

et al. 2019

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Most of the pumps working under two phase flows conditions are used in petroleum industry applications, like electrical submersible pumps (ESP) for hydrocarbon fluids, in chemistry, nuclear industries and in agriculture for irrigation purposes as well. Two-phase flows always deteriorate overall pump performances compared with single flow conditions. Several papers have been published aiming to understand flow physics and to model all the main mechanisms that govern gas pocket formation and surging phenomena. These mechanisms depend on the pump type, the impeller geometry, the rotational speed, design and off-design liquid flow rate conditions, the volumetric gas fraction, the fluid properties and the inlet pressure. In the present paper, a review on two phase performances from various centrifugal pumps designs is presented, mainly based on experimental results. The main focus is devoted to detect the significant geometrical parameters that: (1) Modify the pump head degradation level under bubbly flow regime assumption; (2) Allow single stage centrifugal pumps keep working under two-phase flow conditions with high inlet void fraction values before pump shut down, whatever the pump performance degradations and liquid production rates should be. Because most of the published experimental studies are performed on dedicated laboratory centrifugal pump models, most of the present review is based on air-water mixtures as the working fluid with inlet pressures close to atmospheric conditions. The following review supposes that gas phase is considered as a non-condensable perfect gas, while the liquid phase is incompressible. Both phases are isolated from external conditions: neither mass nor heat transfer take place between the phases.

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“…With the development of computer technology, numerical simulations based on computational fluid dynamics (CFD) are being widely used in engineering optimization design and performance prediction [28]. Stel et al [29] indicated that the displacement of bubbles in an impeller is hindered by the increase in the bubble diameter and impeller speed but facilitated by increase in the liquid flow rate. Furthermore, one can understand the pattern of the bubble trajectories by performing a force analysis.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the impact of the coupling of diffuser parameters on the performance of submersible pumps used in town water distribution systems

Wei

Sun

Shamseldin

2019

J Braz. Soc. Mech. Sci. Eng.

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Diffusers are energy conversion devices in submersible pump structures, and they play a key role in improving the pump performance and operational stability. However, investigations pertaining to the factors influencing the performance of diffusers, in particular the effect of the coupling of factors on the performance of submersible pumps, are still rare. This study focuses on the effect of coupled parameters, such as the inlet angle, inlet width, axial length and number of blades of diffusers, for improving the performance of submersible pumps. First, the orthogonal test method is used to design the diffuser scheme, and sixteen models involving the coupling of different diffuser parameters are established and simulated. Next, the path analysis method is used to extensively understand the effect mode and influence degree of diffuser parameter coupling on the performance of submersible pumps. The results indicate that the mode of action of the diffuser parameters on the performance of the submersible pump can divided into two aspects: the direct action of the parameter itself and the indirect effect of the parameter coupling induced by other parameters. The orders of significance of the parameters affecting the head and efficiency are α 3n > L > b 3 > z and L > α 3n > b 3 > z, respectively. The contribution rates of the inlet angle, inlet width, axial length and number of blades to the pump efficiency are 31.56%, 16.53%, 37.05% and 14.86%, respectively. The numerical results show that the combination of the diffuser parameters-blade inlet angle of 30°, inlet width of 45 mm, axial length of 100 mm and number of blades equal to 8-can help realize the maximum efficiency (83.5%) of a submersible pump with a 18.9 m head. In the production design, the parameters can be quantitatively evaluated in advance by using path analysis. On this basis, the key parameters can be selected according to the order of magnitude of the influence degree. Furthermore, taking into account the production process and manufacturing costs, it is necessary to consider the active role of the non-key parameters in improving the submersible pump performance.

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Investigation of the Motion of Bubbles in a Centrifugal Pump Impeller

Cited by 30 publications

References 25 publications

Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

A Review of Design Considerations of Centrifugal Pump Capability for Handling Inlet Gas-Liquid Two-Phase Flows

Numerical study on the impact of the coupling of diffuser parameters on the performance of submersible pumps used in town water distribution systems

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