• Proceedings of the KSME Conference
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• 2002.08a
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• pp.585-588
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• 2002

Pump casing has blockage effects on Impeller flow in a centrifugal pump such that the flow field around volute tongue has quite large change when the impeller rotates. A double suction pump is widely used in industrial world because it has lower NPSH required than a single suction pump. Thus, in this study, the interaction between impeller and volute casing has been investigated by using CFD for a double-suction centrifugal pump. Quasi-steady method and full pump model has been employed for the numerical calculation.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.74-82
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• 1999

To meet the needs of the hydraulic excavator of large capacity, tandem axial type piston pump which is high pressure and high speed have been developed. But inevitably we can not help facing the problem of noise at that time. In order to reduce the noise of this pump, many researchers have been studying the problem of oil distribution manner. But they are not interested in the symmetric structure of tandem type pump. So, focusing on the symmetric structure of tandem type pump, this paper analyzed unbalanced force developed in the pump chamber and verified the effect of the pumping phase of the piston on vibration and noise of the tandem axial type piston pump theoretically.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.1
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• pp.10-18
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• 2011

In the beginning of this study, pressure in a cylinder and flow rate from a cylinder of a rotating-cam and fixed-cylinder type radial piston pump are investigated through numerical simulations, so that the simulation results might be utilized as basements for examining physical phenomena occurring in the pump assembly. Then, for supplying basic knowledge on pump design, pressure, flow and leakage characteristics of the pump assembly under the variations of major design parameters are investigated through numerical simulations. At the end, key design parameters influencing upon volumetric efficiency of the pump are listed.

• International Journal of Fluid Machinery and Systems
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• v.4 no.1
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• pp.25-32
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• 2011

The objective of present work is to use numerical simulation to investigate the complex three-dimensional and secondary flow structures developed at the inlet and impeller in a centrifugal pump at design and off-design points. The pump impeller is shrouded with 6 backward swept blades and with a specific speed of 0.8574. The characteristic of the pump is measured experimentally with straight and curved intake sections. Numerical computation is carried out to investigate the pump inlet flow structures and subsequently the flow field within the centrifugal pump. The numerical results showed that strong interaction between the impeller eye and intake section. Secondary flow structure occurs upstream at the pump inlet has great influence on the pump performance and flow structure within the impeller.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.256-259
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• 2003

Artificial heart is divided pulsation style and nonpulsation style greatly according to flowing of blood. nonpulsation pump is advantage of miniaturization avaliable because it is simple and non-volumic-pump than pulsation pump. Non pulsation pump is derided axial flow style and centrifugal style accordig to rotating style. An axial flow blood pump can be made smaller than a centrifugal blood pump because of its higher specific speed. A hemolysis is an important factor for the development of an axial flow blood pump. It is difficult to identify the areas where hemolysis nun. Evaluation of hemolysis both in in vitro and in vivo require a long time and are costly. Computational fluid dynamics(CFD) analysis enables the engineer to predict hemolysis on a computer. The aims of this study is Computational fluid dynamics in the whole axial flow pump and to verify the accuracy of prediction results of CFD analysis compare with in vitro experimental results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.1
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• pp.12-19
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• 2000

The multi type heat pump system may provide more energy savings and better environmental conditions than the single type heat pump system may do. In order to design a multi type heat pump system, it may be recommended to develop the system simulation program, which can predict the characteristics of the system such as unit capacities, power consumptions, and system COP's. In this study, the steady state simulation program of the multi type heat pump system was developed. The results from the simulation program were compared with those from the experimental tests which were performed in the environmental chamber, Cooling tests show 3.11% and 0.94% of error in capacity and COP, and heating tests show 3.30% and 1.90% of error in capacity and COP, respectively. Therefore, the steady state simulation program developed for this study can effectively be used for the design and the performance prediction of the multi type heat pump system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.9 no.4
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• pp.1-7
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• 2013

This study is to compare energy consumption of air-source, ground-source and dual-source heat pump systems during intermediate season using dynamic simulation. Ground-source heat pump has higher COP than that of air-source but requires additional power consumption of auxiliary equipment such as circulation pump. During intermediate season when the outdoor air temperature is favorable, total COP of air-source heat pump may be greater than that of ground-source when circulation pump power consumption is included. Dual-source heat pump which selects the more favorable heat source is compared with air-source only and ground-source only heat pumps for total power consumption. Results show that power consumption of dual-source heat pump is lower than that of ground-source only by 0.73%.

• International Journal of Fluid Machinery and Systems
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• v.3 no.2
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• pp.102-112
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• 2010

Artificial heart pumps have attracted the attention of researchers around the world as an alternative to the organ used in cardiac transplantation. Conventional centrifugal pumps are no longer considered suitable for long-term application because of the possibility of occurrence of blood leakage and thrombus formation around the shaft seal. To overcome this problem posed by the shaft seal in conventional centrifugal pumps, the magnetically suspended centrifugal pump has been developed; this is a sealless rotor pump, which can provide contact-free rotation of the impeller without leading to material wear. In Europe, clinical trials of this pump have been successfully performed, and these pumps are commercially available. One of the aims of our study is to numerically examine the internal flow and the effect of leakage flow through the gap between the impeller and the pump casing on the performance of the pump. The results show that the pressure head increases compared with the pump without a gap for all flow rates because of the leakage of the fluid through the gap. It was observed that the leakage flow rate in the pump is sufficiently large; further, no stagnant fluid or dead flow regions were observed in the pump. Therefore, the present pump can efficiently enhance the washout effect.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.428-434
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• 2015

The objective of the present study is to analyze the results of the trial-test for the full-scale driving pump, which is arranged in the LCT (Large Cavitation Tunnel). Firstly, the reasons of selecting the final design pump are introduced in terms of the performance analysis in model tests. The trial-test items for the full-scale driving pump are measurements of output current/voltage at the inverter of the main motor and the flow velocity in the LCT test section. The test results show the increase in flow rate of about 10.7% and the decrease in pump head of about 26%, compared with those of final design-pump specification. The motor power has the margin of about 22%. The performance analysis for the full-scale pump is conducted using the commercial code (CFX-10). The delivered power calculated with CFX-10 shows good agreement with that extracted from the full-scale pump test. It is found that CFX-10 is useful to analyze a full-scale pump.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.386-391
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• 2013

The dynamic characteristics of both raw-water source and air source heat pump utilized in water treatment facilities were investigated by using TRNSYS simulator. The modeling of the raw water source heat pump was verified by the measured data at the Cheongju water treatment facility, and the modeling at the air source heat pump was verified by the data from the Siheung water treatment facility. The average heating and cooling COPs from the raw-water source heat pump were higher than those of the air source heat pump by 19% and 18%, respectively. The power consumptions of the air source heat pump for the cooling and the heating were higher than those of the raw water source heat pump by 28% and 26%, respectively.