• The KSFM Journal of Fluid Machinery
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• v.11 no.6
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• pp.18-23
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• 2008

In this paper, effects of inlet shape on the performance of a submerged cargo pump were numerically studied using a commercial CFD code ANSYS-CFX. The inlet shape, especially the gap between pump and suction well, is an important parameter in a point of view of performances of submerged cargo pump due to its effects on the residual and also hydraulic performance of the pump, respectively. To investigate the optimized gap, the overall performance degradations were calculated with the gap. In addition to that, the flow field through the gap was investigated to explain the effect of velocity non-uniformity on the performance of the pump impeller.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.727-733
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• 2020

Recently, reciprocating cryogenic pumps are mainly developed for small-and-mid sized fuel supply systems. Centrifugal type pumps are not actively developed. Most cryogenic submerged pumps are imported. For transportation, cryogenic liquefied natural gas requires the liquid pump technology that can works in extreme evironments. In order to transport liquefied natural gas, it is necessary to apply pump technology. This is the fundamental research for developing the submerged pump technology applicable to the transportation and storage system equipment of cryogenic liquefied system. It tries to secure basic design materials through reverse-engineering in the cryogenic submerged pump development. Regarding materials, STS-304 and STS-431 which are stainless materials widely used in the cryogenic area are applied. Aluminum alloy is applied to impeller and upper manifolder and the pump rotates at the high speed of 6,000rpm.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.491-496
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• 2005

A pump design system was constructed by several integrating in-house programs and commercial softwares to design and evaluate centrifugal pumps. An agent-based prototype framework has been developed for collaborative design and optimization of a centrifugal pump. This paper introduces the feasible technology needed to construct a pump design system based on software agents. The integrated design system, developed in the present study, was used in designing a centrifugal pump and modifying its impeller shape by using optimization processes to increase the pump performance.

• Journal of Hydrogen and New Energy
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• v.33 no.5
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• pp.583-590
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• 2022

In this paper, the performance characteristics of the 2 vane pump for wastewater treatment were investigated using response surface method(RSM) with commercial computation fluid dynamics(CFD) software. Design variables of wastewater treatment pump were defined with the meridional plane of the 2 vane pump impeller. The objective functions were defined as the total head and the efficiency at the design flow rate. The hydraulic performance of optimum model was verified by numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.310-315
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• 2007

The axial-flow type blood pump(XVAD) which has been developed in our group consists of mechanical parts (an impeller, a diffuser and a flow straightener) and electrical parts (a motor and a magnetic bearing). The magnetic bearing system fully levitates the impeller to remove mechanical coupling with other parts of the pump with constant gap, which needs non-contact type gap sensing. Conventional gap sensors are too large to be adopted to the implantable axial -flow type blood pump. Thus, in this paper, the compact eddy current type gap sensor system proper for the implantable axial-flow type blood pump was developed and its performance was evaluated in vitro. The developed eddy current type gap sensor system is a transformer type and has a differential probe. Sensor coil(probe) has small dimensions(6 mm diameter, 2 mm thickness) and its optimal inductance was determined as 0.068 mH for the measurement range of $0\sim3mm$. It could be manufactured with 130 turns of the 0.04 mm diameter copper coil. The characteristics of the developed eddy current type gap sensor system was evaluated by in vitro experiment. At experiment, it showed satis(actory performance to apply to the magnetic bearing system of the XVAD. It could measure the gap up to 3mm, but the linearity was decreased at the range of $1.8\sim3.0mm$. Moreover, it showed no difference in different media such as the water and the blood at the temperature range of $35\sim40^{\circ}C$.

• International Journal of Fluid Machinery and Systems
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• v.6 no.1
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• pp.11-17
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• 2013

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Blade-to-blade low velocity regions are suppressed in the case with the splitter blades and total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.6
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• pp.409-415
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• 2016

In this study, we test the effects of the surface roughness on the hydro efficiency of double-suction centrifugal pumps ($Q=70.7m^3/min$, H = 87 m). The original surface of the impeller and inner casing were coated, resulting in surface-roughness reductions ranging from $100{\sim}110{\mu}m$ to $0{\sim}0.08{\mu}m$. We conducted experimental studies to measure the efficiency of the pumps and operating-pump electro energy variations with different surface roughness values. The experimental results showed that the efficiency of the pumps increased by about 0.8~1.79% and the electric energy of the operating pump was reduced by around 4.38 ~ 6.08%. These results indicate that the performance of the pumps depend largely on the surface roughness of the impeller and inner casing, and by reducing the surface roughness, we can improve the efficiency of the pump and reduce costs by reducing the electric energy consumption.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1201-1207
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• 2012

This study was performed to develop a high-efficiency submersible nonclogging pump impeller. Toward this end, we simulated the effect of some parameters such as the outlet position of a blade ($h_I$), outlet width of a blade ($b_2$), and hub profile on the pump efficiency by using the commercial codes ANSYS CFX and BladeGen. The results showed that the pump efficiency was proportional up to $h_I$= 38 mm and $b_2$= 55 mm. It remained constant over these values. However, the head and shaft power were proportional to $h_I$ and $b_2$ in the simulated ranges. The effects of hub profile changes on the pump efficiency were relatively small compared to those of the other parameters.

• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.46-52
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• 2015

Pump-turbine system is widely used by the hydropower industry for stabilizing the electrical grid in the vast growing economy of most developed countries. This study only investigates the Fluid-structure Interaction (FSI) analysis of the pump-turbine system at various operating conditions. The FSI analysis can show how reliable each component of the system is by providing the engineer with a better understanding of high stress and deformation points, which could reduce the lifespan of the pump-turbine. Pump-turbine components are categorized in two parts, pressurized static parts and movable stressed parts. The fixed parts include the spiral casing, top and bottom cover, stay vane and draft tube. The movable parts include guide vanes and impeller blades. Fine hexahedral numerical grids were used for CFD calculation and fine tetrahedral grids were used for structural analysis with imported load solution mapping greater than 90 %. The maximum equivalent stress are much smaller than the material yield stress, and the maximum equivalent stress showed an increasing tendency with the varying of operating conditions from partial to excessive at both modes. In addition, the total deformation of all the operating conditions showed a small magnitude, which have quite small influence on the structural stability. It can be conjectured that this system can be safely implemented.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2207-2220
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• 2021

Lead alloy is used as coolant in Lead-based cooled Fast Reactor (LFR). The natural characteristics of lead alloy are combined with the simple structural design of LFR. This constitutes the inherent safety characteristics of LFR. The main work of this paper is to take the main coolant pump (MCP) in the lead-cooled fast reactor (LFR) as the research object, and to study the flow pattern distribution of the internal flow field under the reverse rotation pump condition, the reverse rotation positive-flow braking condition and the reverse rotation negative-flow braking condition. In this paper, the double-outlet volute type and the space guide vane are selected as the potential designs of the CLEAR-I MCP. In this paper, the CFD method is used to study the potential reverse accident of the MCP. It is found that the highest flow velocity in the impeller appears at the impeller outlet, and the Q-H curves of the two design programs basically coincide. The space guide vane type MCP has better hydraulic performance under the reverse rotation positive-flow condition, the Q-H curves of the two designs gradually separate with increasing flow rate, and the maximum flow velocity inside the space guide vane type MCP is obviously lower than that of the double-outlet volute type. For the reverse rotation test of MCP, only the condition of the forward rotating pump of the main coolant pump is tested and verified. For the simulation of the MCP in LBE medium, it proved that the turbulence model and basic settings selected in the simulation are reliable.