• Proceedings of the KSME Conference
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• 2002.08a
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• pp.589-592
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• 2002

A commercial CFD code is applied to analyze the 3-D viscous flow field within vertical multi-stage centrifugal pump including impeller of centrifugal pump with 6 blades and guide vain with 11 blades. The numerical analysis of vertical multi-stage centrifugal pump is performed by changing flow rate from $8\;to\;26\;m^{3}/h$ at the constant 3500rpm. The characteristics such as total pressure coefficient, total head, water horse power, power efficiency are represented according to flow rate changing. In the future, we will need to perform flow calculation of vertical multi-stage centrifugal pump by considering meridional shape of impeller.

• Advances in Computational Design
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• v.6 no.1
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• pp.43-53
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• 2021

Multi-stage pumps are the most popular pumps among various kinds of centrifugal pumps. Athorough review of different kinds of literature has led to the conclusion that there is a desperate need to increase the performance of the multi-stage centrifugal pump. Many investigators have put their efforts to increase the pump performance and also the work is being projected on various aspects of pump performance variables. To improve the multistage centrifugal pump performance by investigation, modification, and analysis many works of literature are available. For analysis, many researchers used the Navier-Stokes solver to create the three-dimensional unsteady turbulent flow numerical model with the standard k-ε turbulent equation. This paper mainly focuses on research related to the multi-stage centrifugal pump.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.6
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• pp.790-796
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• 2003

As a fluid machinery for piping liquid in the reactor cooling system, multi-stage centrifugal pump requires the structural dynamic stability against external dynamic excitation. This paper is concerned with the finite element analysis of its eigen behavior and seismic response to RRS(Required Response Spectrum) curves in the case of SSE (Safe Shutdown Earthquake). Through the finite element analysis, the major vibration characteristics of multi-stage centrifugal pump(MSCP) are investigated and seismic qualification based on the IEEE codes is executed. The numerical results show that the MSCP used in this study has enough seismic strength.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.402-407
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• 2002

A commercial CFD code is applied to analyze the 3-D viscous flow field within vertical multi-stage centrifugal pimp including impeller with 6 blades and guide vane with 11 blades and is performed by changing flow rate from 10 to $26\;m^3/h$ at the constant 3500rpm. The purpose of this 3-D numerical simulation is to confirm how much the effect of blade inlet angle of guide vane has an influence on the performance of vertical multi-stage centrifugal pimp. these results performed by $20^{\circ},\;30^{\circ}$ inlet angle of guide vane are compared with grundfos performance data. The vertical multi-stage pump consist of the impeller, guide vane, and cylinder. The characteristics such as total pressure coefficient total heat shaft horse power, power efficiency, discharge coefficient are represented according to flow rate changing.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.150-155
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• 2002

A commercial CFD code is applied to analyze the 3-D viscous flow field within vertical multi-stage centrifugal pump including impeller with 6 blades and guide vane with 11 blades and is performed by changing flow rate from 10 to $26m^3/h$ at the constant 3500rpm. The purpose of this 3-D numerical simulation is not only to confirm how much the effect of three kinds of blade inlet breadth (11mm, 11.5mm, 12mm) of impeller has influence on the performance of vertical multi-stage pump but also to make clear the cause about performance difference at the exit side of impeller and guide vane. The vertical multi-stage pump consisit of the impeller, guide, vane and cylinder. The grid of numerical analysis used to the vertical multi-stage pump is 18,000, 45,000, and 100000 cells in case of the impeller, guide vane, cylinder and total grid is 730,000 cells. The characteristics such as total pressure coefficient, total head, shaft horse power, power efficiency at the exit side of impeller and guide vane, discharge coefficient are represented according to flow rage changing.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.1-6
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• 2015

Centrifugal pumps consume considerable amount of energy in various industrial applications. Therefore, improvement of the efficiency of these machines has become a major challenge. Cavitation is a phenomenon which decreases the pump efficiency and even causes structural demage. Hence, the goal of this paper is to investigate the cavitation problem in the single-stage and double-stage centrifugal pumps. The Volume of Fraction (VOF) method has been used for the numerical simulations together with Rayliegh-Plesset model for the gas-liquid two-phase flow inside the pump. In order to capture the turbulent phenomena, the standard k-${\varepsilon}$ turbulence model has been adopted, and the simulations have been done as unsteady cases. In addition, the motion of the rotating parts has been simulated using Multi Reference Frame(MRF) method. The results are presented and compared in terms of hydraulic head and NPSH for both the single-stage and double-stage pumps. The H-Q curves show the effects of cavitation on decreasing the pumps performances.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.177-184
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• 2001

For two kinds of the multi-stage centrifugal pump with diffuser vanes and return channel vanes the meanline performance prediction is applied to get information of hydraulic performance at each internal flow station, because only flange-to-flange test curves are available. As a first step of redesign fur higher efficiency, the impeller geometry is numerically investigated in the present study. Quasi-3D inviscid loading distributions are obtained, for the two impellers, using the state-of-the-art method of impeller 3D design, which provides a guide to optimal redesign. Full 3D turbulent flow fields are thereafter analyzed, using the specialized CFD code, to confirm the redesign results. The inherent limitation of the traditional graphic method of impeller design, which most of domestic pump manufacturers are now employing, is found.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.102-110
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• 1998

The analysis of lateral hydrodynamic forces in the leakage path between a shrouded pump impeller through wear-ring seal and its housing is presented. Governing equations are derived based on Bulk-flow and Hirs' turbulent lubrication model. By using a perturbation analysis and a numerical integration method, governing equations are solved to yield leakage and rotordynamic coefficients of force developed by the impeller shroud and wear-ring seal. The variation of rotordynamic coefficients of pump impeller shroud and wear-ring seal is analyzed as parameters of rotor speed, pressure difference, shroud clearance, wear-ring seal clearance, and circumferential velocity at the entrance of impeller shroud for a typical multi-stage centrifugal pump.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.81-85
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• 2015

The purpose of this study is to evaluate energy savings for inverter driving multi-stage centrifugal pump. Variable speed driving pump system has high efficiency compared with constant speed driving pump system. Because of difficulty to estimate operating efficiency of variable speed driving pump system, energy saving rates are used to replace operating efficiency. energy saving rates are calculated from pump input power and pump duty cycle. But another researches have used pump duty cycles of each season for energy saving rate. In this study, for estimating energy saving rate more high accuracy, pump duty cycles are measured for 1 year. pump duty cycles, depending on the season and be classified according to the weekday/weekend or during the week day. By this pump duty cycles, Energy saving rate is calculated appropriately.

• The KSFM Journal of Fluid Machinery
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• v.12 no.6
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• pp.7-12
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• 2009

This paper presents a numerical study on the design of side-suction inlet geometry which is used for multi stage centrifugal pumps or inline centrifugal pumps. In order to achieve an optimum inlet geometry and to explain the interactions between the different geometric configurations, the three dimensional computational fluid dynamics and the design of experiment methods have been applied. Geometric design variables describing the cross sectional area distribution through the inlet were selected. The objective functions are defined as the non-uniformity of the velocity distribution at the passage exit which is just in front of the impeller eyes. From the 2k factorial design results, the most important design variable was found and the performance of the side suction inlet was improved compared to the base line shape.