• Journal of Drive and Control
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• v.15 no.4
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• pp.23-29
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• 2018

The objective of this paper is to evaluate the reliability of a volute pump and presents test results through performance and life tests. The performance and life test methods were presented by analyzing the failure modes of the volute pump. Zero failure test time was calculated to evaluate the reliability of the volute pump and then, the test was performed under accelerated conditions. The test was also carried out to check the failure modes of the field conditions. This study can be provided to improve the product reliability through failure analysis of the volute pump. And failure cause of typical failure case has been investigated and improvement design has been presented. The performance test results of before and after the accelerated life test were presented to confirm the improved reliability of the volute pump.

• The KSFM Journal of Fluid Machinery
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• v.9 no.2 s.35
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• pp.44-49
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• 2006

In this study, the effects of volute area distribution on the performance of a centrifugal pump were numerically studied using a commercial CFD code. To reduce the shutoff head, maintaining head and efficiency at a design flow rate, the flat head-capacity characteristic curves in which the head varies only slightly with capacity from shutoff to design capacity are frequently required. In order to control the shutoff head of a pump, several volute cross-sectional area distributions were proposed as a main parameter with the same impeller geometry The calculation results show that the slope of the performance characteristic curve of the centrifugal pump can be controlled by modifying the area distribution from volute tongue to volute outlet with fixed volute outlet area and also varied volute outlet area.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.497-502
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• 2005

In this study. the effect of volute area distribution on the performance of a centrifugal pump were numerically studied using a commercial CFD code. To reduce the shutoff head, maintaining head and efficiency at a design flow rate. the flat head-capacity characteristic curves in which the head varies only slightly with capacity from shutoff to design capacity are frequently required. In order to control the shutoff head of a pump, several volute cross-sectional area distributions were proposed as a main parameter with the same impeller geometry. The calculation results show that the slope of the performance characteristic curve of the centrifugal pump can be controlled by modifying the area distribution from volute tongue to volute outlet with fixed volute outlet area and also varied volute outlet area.

• The KSFM Journal of Fluid Machinery
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• v.3 no.4 s.9
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• pp.7-14
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• 2000

This paper provides integrity evaluation and root cause analysis for defects observed at volute tongue, or cutwater, of the operating centrifugal pump in power plant. The cause of the cracks are analyzed and reviewed from the viewpoint of the operation and maintenance of the pumps, and the sample obtained from the cracked volute tongue of the pump are examined. At first, in-situ hardness test and microstructure examination were performed to understand the cause of cracking at volute tongue. The evaluation of structural integrity and the possibility of the crack propagation is also evaluated. Cracks were typical intergranular cracking and propagated along with prior austenite grain boundary. At easing volute tongue, the hardness was higher than ASTM requirement and a large amount of intergranular Cr carbide was precipitated. These were due to high C content in material. P content was also higher than ASTM requirement. Therefore, Cr carbide precipitation and P segregation at grain boundary, caused by higher C and P content in material, resulted in intergranular cracking of casing volute tongue. This procedure for integrity evaluation and root cause analysis is used to guide, and support the pump designer and manufacturer's material selection and process design to avoid a costly, unplanned outage of plant.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.218-226
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• 2017

Severe radial thrust under off-design operating conditions can be a harmful factor for centrifugal pumps. In the present work, effects of geometry of a double volute casing on the hydrodynamic performance of a centrifugal pump have been investigated focusing on off-design conditions. Three-dimensional steady Reynolds-averaged Navier-Stokes analysis was carried out by using shear stress transport turbulence model. Numerical results for the hydrodynamic performance of the centrifugal pump were validated compared with experimental data. The hydraulic efficiency and radial thrust coefficient were used as performance parameters to evaluate the hydrodynamic characteristics of the centrifugal pump. The cross-sectional area ratio of the volute casing, the expansion coefficient of the rib structure, the distance between the rib starting point and volute entrance, and radius and width of the volute entrance, and length of the rib structure, were selected as geometric parameters. Results of the parametric study show that the performance parameters are significantly affected by the geometric variables and operating conditions. Optimal configurations of the double volute casing based on the design of experiments technique show outstanding performance in terms of the efficiency and radial thrust coefficient.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.39-45
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• 2012

In this study, optimization of the impeller and design of volute were carried out in order to improve the performance of a centrifugal pump. Design parameters from vane plane development for impeller design were selected, and effect of the design parameters on the performance of the pump was analyzed by using Response Surface Methodology(RSM) to optimized impeller. In addition, total pump design method was suggested by designing volute which was suitable for the optimized impeller through volute design where Stepanoff theory was applied and numerical analysis.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.558-563
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• 2005

In this paper, the effect of volute area distribution on the performance characteristic curve of a centrifugal pump were numerically studied using a commercial CFD code. To reduce the shutoff head, maintaining head and efficiency at a design flow rate, the flat head-capacity characteristic curves in which the head varies only slightly with capacity from shutoff to design capacity are frequency required. In order to control the shutoff head of a pump, several volute area distributions were proposed as a main parameter with the same impeller geometry. The calculation results show that the characteristic curve of a centrifugal pump can be controlled by modifying the area distribution with the same volute outlet area.

• International Journal of Fluid Machinery and Systems
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• v.4 no.4
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• pp.375-386
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• 2011

The turbo-type blood pump studied in this paper has an impeller that is magnetically suspended in a double volute casing. The impeller rotates with minimal fluctuations caused by fluid and magnetic forces. In order to improve stability of the rotating impeller and to facilitate long-term use, a careful investigation of the pressure fluctuations and of the fluid force acting on the impeller is necessary. For this purpose, two models of the pump with different volute cross-sectional area are designed and studied with computational fluid dynamics software. The results show that the fluid force varies with the flow rate and shape of the volute, that the fluctuations of fluid force decrease with increasing flow rate and that the vibratory movement of the impeller is more efficiently suppressed in a narrow volute.

• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.203-208
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• 2001

Any circumferential variations of the impeller exit flow conditions influences on the volute inlet flow conditions. All these interactions are strongly coupled phd affect consequently the performance of centrifugal pumps. In this paper, a commercial CFD code, which solves three-dimensional quasi-steady Wavier-Stokes equations with an impeller/volute interaction, is used for the prediction of a centrifugal pump performance. The simplified model of an impeller/volute interaction requires affordable computing time and provides relevant results. As a result, detailed flow structures such as pressure rise, recovery and loss mechanism on the centrifugal pumps are obtained. Especially, hydraulic performances are compared between the case of impeller only and the case of impeller with volute configuration. In addition, pump performance at off-design operation are observed and discussed.

• International Journal of Fluid Machinery and Systems
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• v.4 no.3
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• pp.349-359
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• 2011

An unsteady numerical analysis has been carried out to study the strong impeller volute interaction of a centrifugal pump with six backward swept blades shrouded impeller. The numerical analysis is done by solving the three-dimensional Reynolds Averaged Navier-Stokes codes with standard k-${\varepsilon}$ two-equations turbulence model and wall regions are modeled with a scalable log-law wall function. The flow within the impeller passage is very smooth and following the curvature of the blade in stream-wise direction. However, the analysis shows that there is a recirculation zone near the leading edge even at design point. When the flow is discharged into volute casing circumferentially from the impeller outlet, the high velocity flow is severely distorted and formed a spiraling vortex flow within the volute casing. A spatial and temporal wake flow core development is captured dynamically and shows how the wake core diffuses. Near volute tongue region, the impeller/volute tongue strong interaction is observed based on the periodically fluctuating pressure at outlet. The results of existing analysis also proved that the pressure fluctuation periodically is due to the position of impeller blade relative to tongue.