Numerical prediction of impacts of cavitation in pumps for power generation

Sedlář, Milan; Šoukal, Jiří; Krátký, Tomáš; Vyroubal, Michal

doi:10.1134/s0040601515060087

Cited by 6 publications

(3 citation statements)

References 5 publications

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“…수면 아래에서 TNT(trinitrotoluene), 펜톨라이트와 같은 폭발물 의 폭발로 발생한 버블은 맥동과 동시에 연직 상승하고 함정과 의 상호작용에 의한 버블젯 현상 등에 의해 큰 피해를 초래한 다 (Zhang et al, 2011a;Zhang et al, 2011b (Brennen, 1995;Zhang et al, 2013 (Sedlář et al, 2015;Sreedhar et al, 2017;Taskar et al, 2017;Zhang et al, 1989 (Klaseboer et al, 2005). 경계요소법을 이용하여 수치적으로 계산된 속도 포텐셜은 버블 표면과 구조물 표면에 서 속도 경계조건을 만족하도록 하였다 (Chahine and Perdue, 1990).…”

Section: 서 론unclassified

Analysis of Velocity Potential around Pulsating Bubble near Free or Rigid Surfaces Based on Image Method

이¹,

최²,

김³

et al. 2018

J. Ocean Eng. Technol.

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An analytical method for predicting the velocity potential around a pulsating bubble close to a free or rigid wall was established using an image method. Because the velocity potential should satisfy two boundary conditions at the bubble surface and rigid wall, we investigated the velocity in the normal direction at the two boundaries by adding the image bubbles. The potential was analyzed by decomposing the bubble motion as two independent motions, pulsation and translation, and we found that when the number of image bubbles was greater than ten, the two boundary conditions were satisfied for the translation term. By adding many image bubbles after the approximation of the pulsation term, we also confirmed that the boundary condition at the wall was satisfied.

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Section: 서 론unclassified

Analysis of Velocity Potential around Pulsating Bubble near Free or Rigid Surfaces Based on Image Method

이¹,

최²,

김³

et al. 2018

J. Ocean Eng. Technol.

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“…Concerning the mathematical simulations of a complete pumping system with the siphon outlet, some published studies describe the flow inside the system as a single-phase one, e.g., [1]. More recent simulations consider also the influence of the free water level, e.g., [2]. They use usually the volume of fluid (hereinafter VOF) multiphase model.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research and Numerical Analysis of Flow Phenomena in Discharge Object with Siphon

Sedlář¹,

Procházka

Komárek³

et al. 2020

Water

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This article presents results of the experimental research and numerical simulations of the flow in a pumping system’s discharge object with the welded siphon. The laboratory simplified model was used in the study. Two stationary flow regimes characterized by different volume flow rates and water level heights have been chosen. The study concentrates mainly on the regions below and behind the siphon outlet. The mathematical modelling using advanced turbulence models has been performed. The free-surface flow has been carried out by means of the volume-of-fluid method. The experimental results obtained by the particle image velocimetry method have been used for the mathematical model validation. The evolution and interactions of main flow structures are analyzed using visualizations and the spectral analysis. The presented results show a good agreement of the measured and calculated complex flow topology and give a deep insight into the flow structures below and behind the siphon outlet. The presented methodology and results can increase the applicability and reliability of the numerical tools used for the design of the pump and turbine stations and their optimization with respect to the efficiency, lifetime and environmental demands.

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“…In previous studies, it was found that the swirling flows and vortex motions within unshrouded impellers are sensitive to the tip clearance flow. In the study of mixed-flow pump, structure design and optimization [7][8][9], flow field measurement and analysis [9,10], hydraulic and cavitation performances prediction [11][12][13][14] were investigated. Kim et al [15] performed numerical simulation to investigate the tip clearance effect on the pump head and hydraulic efficiency.…”

mentioning

confidence: 99%

Effect of a Nonuniform Radial/Axial Tip Clearance on the Flow Field in a Mixed-Flow Pump

Shi

et al. 2018

Strength Mater

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The effect of a nonuniform radial/axial tip clearance on the flow field in a mixed-flow pump was studied by numerical simulation of the unsteady flow in the pump with two tip clearance shapes using the standard Reynolds average Navier-Stokes turbulence model, and the equations were solved with the SIMPLEC computational algorithm. The external characteristics, distribution of static pressure, streamline flow of the tip clearance, and vorticity in the impeller are analyzed. The accuracy of numerical simulation was assessed by comparing experimental data with computational results. Although a nonuniform tip clearance leads to a decline in the pump head, which is more pronounced under part-load conditions, the configuration with a nonuniform tip clearance (c = 0.5-1 mm) provides the more uniform velocity and pressure distribution both in the circumferential and axial directions, as the leakage vortex intensity is weakened and its shedding is suppressed. The research results pointed the way for improving the unsteady flow in the mixed-flow pump.

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Numerical prediction of impacts of cavitation in pumps for power generation

Cited by 6 publications

References 5 publications

Analysis of Velocity Potential around Pulsating Bubble near Free or Rigid Surfaces Based on Image Method

Analysis of Velocity Potential around Pulsating Bubble near Free or Rigid Surfaces Based on Image Method

Experimental Research and Numerical Analysis of Flow Phenomena in Discharge Object with Siphon

Effect of a Nonuniform Radial/Axial Tip Clearance on the Flow Field in a Mixed-Flow Pump

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