Numerical analysis of unsteady tip leakage vortex cavitation cloud and unstable suction-side-perpendicular cavitating vortices in an axial flow pump

Zhang, Desheng; Shi, Lei; Shi, Weidong; Zhao, Ruijie; Wang, Hai‐Yu; Esch, B.P.M. van

doi:10.1016/j.ijmultiphaseflow.2015.09.006

Cited by 150 publications

(79 citation statements)

References 38 publications

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“…Zhang et al [10][11][12] numerally investigated the tip leakage vortex structure and trajectory in an axial flow pump by combining the shear stress transport k-ω turbulence model with a cavitation model. Yang et al [13] used the standard k-ε turbulence model to investigate the effect of the radial gap between impeller tips and volute tongue on efficiency and pressure pulsation of pumps used as turbines.…”

Section: Introductionmentioning

confidence: 99%

Energy Performance and Flow Patterns of a Mixed-Flow Pump with Different Tip Clearance Sizes

et al. 2017

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Tip clearance between blade end and shroud is inevitable in pump operation and of great importance on pump energy performance and pressure fluctuation. As the tip clearance size increases, the head and efficiency of the mixed flow pump drop accordingly. The simulation results show that the development of a leakage vortex is observed as the tip clearance increases, and the trajectory of this leakage vortex remains in the same direction along the blade suction side for different tip clearances. With the increase in tip clearance size, the intensity of the leakage vortex is enhanced, and the separation between the main leakage vortex and the secondary leakage vortex is also strengthened. The leakage separation angle near the blade tip remains at the same value of 10° for different tip clearance sizes. As for the spectrum analysis, the maximum amplitudes of pressure fluctuations dramatically increase in the impeller when the tip clearance increases from 0.0 mm to 1.0 mm, and the dominant frequencies go from 145 Hz to 184 Hz due to the considerable leakage flow.

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Section: Introductionmentioning

confidence: 99%

Energy Performance and Flow Patterns of a Mixed-Flow Pump with Different Tip Clearance Sizes

et al. 2017

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“…By numerical simulation based on cavitation model, the area and location of bubbles can be predicted [20], and then validated by comparison with experimental observation through highspeed photography [21] [29] simulated and analysed 3-D tip leakage vortex cavitation and the suction-side-perpendicular cavitating vortices in an axial pump by applying Zwart model and an improved SST k-ω turbulence model, the simulation results matched well with high speed photography results. Since many cavitation models are embedded with commercial solvers, it becomes convenient and efficient to model cavitation for fluid machinery, as was stated above.…”

Section: Introductionmentioning

confidence: 68%

Numerical investigation of cavitation in twin-screw pumps

Yan

Kovačević

Tang

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part C:

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This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent repository link AbstractIn order to investigate the flow characteristics and the formation process of cavitation in twinscrew pumps, three-dimensional CFD (Computational Fluid Dynamics) numerical analysis has been carried out. A conformal structured moving mesh generated by an in-house code SCORG was applied for the rotor domain. The VOF (Volume of Fluid) Method has been adopted for dealing with the liquid-gas two-phase flow, while the bubble dynamics was handled by a homogenous cavitation model. By changing the rotation speed and discharge pressure, the intensity, distribution area and variation of cavitation at different rotor angle were obtained. The effects of rotation speed and discharge pressure on cavitation characteristics have been analysed. Calculation results with cavitation model are compared with the results without cavitation and the experimentally obtained values. The influence of cavitation on the performance of a screw pump in terms of the mass flow rate, pressure distribution, rotor torque and the shaft power have been analysed and discussed. For analysis of cavitation in clearances, a 2-D numerical model which includes radial and inter-lobe clearances was used. The relationship between volumetric efficiency and cavitation intensity was developed by variation of boundary conditions.

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“…For the purpose of predicting the pump performance under cavitation state before manufacturing or optimizing, many efforts have been made on simulating cavitating flow in pump, since the computational capabilities gains great development in decades. Various computing methods were investigated to solve the vaporization and condensation procedures, among which the homogeneous equilibrium flow method was considered as one of the best approach for simulating the cavitating flow in all kinds of circumstances [11][12][13][14][15][16][17][18][19]. It assumes the flow to be homogenous, treating the liquid and vapor as a mixture.…”

Section: Introductionmentioning

confidence: 99%

Rotating Corrected-Based Cavitation Model for a Centrifugal Pump

Wang

Liu

et al. 2018

Journal of Fluids Engineering

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Cavitation has bothered the hydraulic machinery for centuries, especially in pumps. It is essential to establish a solid way to predict the unsteady cavitation evolution with considerable accuracy. A novel cavitation model was proposed, considering the rotating motion characteristic of centrifugal pump. Comparisons were made with three other cavitation models and validated by experiments. Considerable agreements can be noticed between simulations and tests. All cavitation models employed have similar performance on predicting the pump head drop curve with proper empirical coefficients, and also the unsteady cavitation evolution was well solved. The proposed rotating corrected-based cavitation model (rotating based Zwart-Gerber-Belamri (RZGB)) obtained identical triangle cavity structure with the experiment visualizations, while the others also got triangle structure but with opposite direction. The maximum flow velocity in the impeller passage appears near the shroud, contributing to the typical triangle cavity structure. A preprocessed method for instant rotating images was carried out for evaluating the erosion risk area in centrifugal pump, based on the standard deviation of gray level. The results imply that the unsteady rear part of the attached cavity is vulnerable to be damaged, where the re-entrant flow was noticed. This work presented a suitable cavitation model and reliable numerical simulation approach for predicting cavitating flows in centrifugal pump.

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Numerical analysis of unsteady tip leakage vortex cavitation cloud and unstable suction-side-perpendicular cavitating vortices in an axial flow pump

Cited by 150 publications

References 38 publications

Energy Performance and Flow Patterns of a Mixed-Flow Pump with Different Tip Clearance Sizes

Energy Performance and Flow Patterns of a Mixed-Flow Pump with Different Tip Clearance Sizes

Numerical investigation of cavitation in twin-screw pumps

Rotating Corrected-Based Cavitation Model for a Centrifugal Pump

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