• The KSFM Journal of Fluid Machinery
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• v.4 no.1 s.10
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• pp.38-45
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• 2001

A commercial CFD code is used to compute the 3-D viscous flow field within the impeller of a centrifugal pump. Several preliminary numerical calculations are carried out to determine the influence of the parameters such as the grid systems, the numerical schemes, the turbulence models and the shape of the vaneless diffusers at the design flow rate. The results of the preliminary study are used for the calculation of the off-design flow conditions. The circumferentially averaged results such as the radial and tangential velocities, the exit flow angle, the slip factor, the static pressure and the total pressure are compared with the experimental data at the impeller exit to discuss the influence of the prescribed parameters.

• The KSFM Journal of Fluid Machinery
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• v.5 no.3 s.16
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• pp.25-32
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• 2002

Structural and dynamic analyses of inducer and impeller for an oxidizer turbopump are peformed to investigate the safety level of strength and vibration at a design point. Due to high rotational speed of turbopump, effects of centrifugal forces are carefully considered in the structural analysis. Hydrodynamic pressure is also considered as an external force applied to inducer and impeller blades. A three-dimensional Finite Element Method (FEM) is used for linear and nonlinear structural analyses with modified Newton-Raphson iteration method. After the nonlinear trim solution is obtained from the structural analysis, dynamic characteristics are obtained as a function of rotational speed from the linearized eigenvalue analysis at an equilibrium position. According to the results of numerical analysis, the safety margins of strength and vibration resonances are sufficient enough for safe operation within the requited life cycle.

• The KSFM Journal of Fluid Machinery
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• v.12 no.3
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• pp.7-12
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• 2009

In this paper, shape optimization based on three-dimensional flow analysis has been performed for impeller design of centrifugal compressor. To evaluate the objective function of an isentropic efficiency, Reynolds-averaged Navier-Stokes equations are solved with SST (Shear Stress Transport) turbulence model. The governing equations are discretized by finite volume approximations. The optimization techniques based on the radial basis neural network method are used for the optimization. Latin hypercube sampling as design of experiments is used to generate thirty design points within design space. Sequential quadratic programming is used to search the optimal point based on the radial basis neural network model. Four geometrical variables concerning impeller shape are selected as design variables. The results show that the isentropic efficiency is enhanced effectively from the shape optimization by the radial basis neural network method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.56-62
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• 2017

In this research, reverse engineering was applied to the product manufactured by "Vanzetti" from Italy to develop a localized cryogenic submerged pump used in small-scale LNG liquefaction plants. The results of modal analysis of the impeller and shaft confirmed that the resonance frequency of the impeller and shaft played an important role in the rotor. Modal analysis of the rotor confirmed that the forcing frequency had no influence on the resonance phenomenon.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.63-68
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• 2001

A numerical analysis to predict the flow characteristics in turbo fan for vacuum cleaner has been performed by using CFD. The rotating reference frame method is applied to compute the impeller-diffuser interaction and the characteristics of two models, 460 and 380, are calculated for various rotating speeds and flow rates. The flow in impeller, diffuser and return channel is assumed as steady and compressible. STAR-CD with k- $\epsilon$ turbulence model is used to solve the Navier-Stokes equations. Computed relative velocity, absolute pressure and flow angles are shown and compared with measurement results. The good agreement between the predictions and measurement results confirms the validity of this study.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.271-278
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• 2001

Structural and dynamic analyses of inducer and impeller for a oxidizer turbopump are peformed to investigate the safety level of strength and vibration at design point. Due to high rotational speed of turbopump, effects of centrifugal forces are carefully considered in the structural analysis. Hydrodynamic pressure is also considered as an external force applied to inducer and impeller blades. A three dimensional finite element method(FEM) is used for linear and nonlinear structural analyses with modified Newton-Raphson iteration method. After the nonlinear trim solution is obtained from the structural analysis, dynamic characteristics are obtained as a function of rotational speed from the linearized eigenvalue analysis at an equilibrium position. According to the results of numerical analysis, the safety margins of strength and vibration resonances m sufficient enough to be operated safely within the required life cycle.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.305-311
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• 2000

A commercial CFD code is used to compute the 3-D viscous flow field within the impeller o( a centrifugal pump. Several preliminary numerical calculations are carried out to determine the influence of the parameters such as the grid systems, the numerical schemes, the turbulence models and the shape of the vaneless diffusers at the design flow rate. The results of the preliminary study are used for the calculation of the off-design flow conditions. The circumferentially averaged results such as the radial and tangential velocities, the exit flow angle, the slip factor, the static pressure and the total pressure are compared with the experimental data at the impeller exit to discuss the influence of the prescribed parameters.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.43-48
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• 2004

A screw-type centrifugal pump was manufactured to carry solids primarily and its impeller has a wide flow passage. However, the effect of flow passage shape on delay of the choke due to entrained air has not been clarified yet. Moreover, because its impeller has a particular shape, only few studies have tried to clarify the pump performance and details of internal flow pattern of that pump. For that reason, we carried out the pump performance experiment under air-water two-phase flow condition with different impeller tip clearances, pump rotational speeds and void fractions by using a small screw-type centrifugal pump designed to acquire basic data. In a general centrifugal pump, it was reported that loss of pump head from single-phase flow to the choke due to air entrainment new the best efficiency point was large. However, the loss near the best efficient point in a screw-type centrifugal pump became less than that in a general centrifugal pump.

• Corrosion Science and Technology
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• v.10 no.6
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• pp.218-224
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• 2011

The fresh water and sea water in present ships is used as cooling water for marine engine. Therefore, corrosion damage in seawater system is frequently occurred. In particular, in the impeller of pump, the performance and material span due to the corrosion and cavitation erosion has adverse effects. Most of the pump impellers in vessels are used Cu-Al alloy. Cu-Al alloy which having the excellent mechanical properties and corrosion resistance is widely used in marine environments. However, despite the excellent characteristics, the periodic replacement parts due to the cavitation damage in seawater is vulnerable to economic viewpoint. In this study, Cu-Al alloy used with impeller for centrifugal pump were conducted various experiments to evaluate its characteristics in seawater and fresh water solutions. As an electrochemical result, the dynamic conditions that exposed to the cavitation environment presented high corrosion current density with collapse of the cavity compared with the static conditions. Cavitation test results, the weightloss and weightloss rate in fresh water are observed more than those of seawater.

• The KSFM Journal of Fluid Machinery
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• v.16 no.6
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• pp.12-18
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• 2013

This paper presents the performance characteristics of a centrifugal blower using the design parameters of an impeller blade. Two design variables, the bending length from the blade trailing edge and bending angles of an impeller blade, are introduced to analyze the effects on the blower performance. Three-dimensional Navier-Stokes equations with shear stress transport turbulence model are introduced to analyze the performance and internal flow of the blower. Relatively good agreement between experimental measurements and numerical simulation at the design flow condition is obtained. Throughout present study, it is known that pressure increases as the bending length from the trailing edge and bending angle increase while efficiency decreases. But efficiency is decreased. Detailed flow field inside the centrifugal blower is also analyzed and compared.