• 한국유체기계학회 논문집
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• 제13권6호
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• pp.51-56
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• 2010

A numerical simulation is carried out to investigate the effect of flow rate variation and performance characteristics of double-suction centrifugal pump. Two types of pump which have different impeller inlet breadth and curvature of the shroud line consist of six blades impeller and shroud ring. Finite-volume method with structured mesh and $k-\omega$ Shear Stress Transport turbulence model was used to guaranty more accurate prediction of turbulent flow in the pump impeller. Total head, power and overall efficiency were calculated to obtain performance characteristics of two types of pump according to the variation of flow rate. From the results, impeller having smooth curve along the shroud line obtained good performance. The lower flow rate, the more circulation region, flow unsteadiness and complicate flow pattern are observed. Complicated internal flow phenomena through impellers such as flow separation, pressure loss, flow unsteadiness and performance are investigated and discussed.

• 수산해양기술연구
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• 제35권4호
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• pp.428-434
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• 1999

Experimental studies on the characteristics of annular jet pump were carried out in this paper. Jet pump can be used widely for the transportation of solid materials, farm produce and fishes. The effects of high pressure chamber on the characteristics of annular jet pump were sought in this paper. Experiments were done for three shapes of high pressure chamber, and for several lengths of the high pressure chamber. Three types of the high pressure chamber's entrances($90^{\circ}$ single inflow, $45^{\circ}$single inflow, and $45^{\circ}$ double inflow) were tested. Water was used for both the primary fluid and secondary fluid. The results obtained in this study are as follows; $45^{\circ}$double inflow type is the most effective among the tested three types of the high pressure chamber's entrances. The efficiency of jet pump with 400mm of high pressure chamber length is the highest among the chamber lengths tested in this study, thus indicating appropriate chamber length is required to get an efficient.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1203-1208
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• 2009

In this paper, the flow characteristics of the mixed-flow pump impellers and diffusers were numerically predicted by commercial CFD software and DOE(design of experiments). We also discussed how to improve the performance of the mixed-flow pump by designing the impeller and diffuser in the mixed-flow pump. Geometric design variables were defined by the vane plane development which indicates the blade-angle distributions and length of the impeller and the diffusers. Firstly, the design optimization of the defined impeller geometric variables has been done. After that, the flow characteristics were analyzed in the point of incidence angle at the diffuser leading edge for the optimized impeller. Then design of the defined diffuser shape variables has been performed. The reason for the performance improvement was discussed by examining the flow characteristics through the diffuser.

• 대한기계학회논문집B
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• 제32권4호
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• pp.266-274
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• 2008

The need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as Liquefied Petroleum Gas(LPG) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to apply it for the conventional gasoline or diesel fuel pump directly. In this study, experiments are performed to get performance and efficiency of the fuel pump at different condition as temperature, rotating speeds, composition of fuel. The characteristics of fuel pump is affected by cavitation due to the variation of temperature and composition.

• 한국유체기계학회 논문집
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• 제15권5호
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• pp.5-10
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• 2012

An experimental test facility for the complete characteristics of pumps is constructed at KIMM(Korea Institute of Machinery and Materials). All sensors instrumented in test facility for measuring flow rate, pressure, force and moment are in-situ calibrated by primary method. This paper describes the test facility and test technique of the complete characteristics of pumps, together with an experimental test results for a reactor coolant pump which is designed at KIMM for the first time in Korea. The test results for the mixed-flow type pump of $n_s$=1.425 are presented by three curves: constant head, torque, and speed.

• 한국화재소방학회논문지
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• 제33권3호
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• pp.56-62
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• 2019

본 논문은 규정 유량, 양정, 회전수 및 비속도가 각각 0.7 ㎥/min, 8 m, 1750 rpm, 182 m, ㎥/min, rpm인 원심펌프의 운전시 펌프의 회전수와 유량의 변화가 펌프의 운전특성에 미치는 영향을 고찰하였다. 실험에 사용된 펌프는 안내깃이 없고 외주에 바로 접하여 와류실이 있는 볼류트 펌프를 회전수 1350 rpm에서 1750 rpm까지 100 rpm씩의 회전수 변화 5단계에 따른 H-Q특성, L-Q특성, 𝜂-Q특성 등의 관계와 무차원 성능 특성인 양정계수, 동력계수, 효율 등의 특성을 실험을 통하여 다음과 같은 결론을 얻었다. 회전수의 증가에 따라 펌프 성능의 변화정도를 추정할 수 있고, 펌프의 최대효율은 1450 rpm일 때 유량 0.165 ㎥/min, 양정 4.73 m에서 약 52%, 최대 회전수인 1750 rpm일 때 유량 0.183 ㎥/min, 양정 6.72 m에서 약 50%의 효율이 나타난다. 또한 양정 대 유량의 성능 특성 곡선상에서 등효율 곡선은 펌프의 상사법칙에 따른 원점을 지나는 2차식의 곡선으로 나타나지 않고 타원형으로 변형되어 나타난다. 마지막으로 유량계수가 증가함에 따라 동력계수는 증가하고 양정계수는 감소하며, 유량계수가 0.08일 때 최대효율 52% 되는 것을 통해 유량변화가 운전특성에 미치는 영향을 알 수 있다.

• Nuclear Engineering and Technology
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• 제40권3호
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• pp.213-224
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• 2008

The pumping of coolant in a liquid metal fast reactor may be performed with an annular linear induction electro-magnetic (EM) pump. Linear induction pumps use a traveling magnetic field wave created by poly-phase currents, and the induced currents and their associated magnetic field generate a Lorentz force, whose effect can be the pumping of the liquid metal. The flow behaviors in the pump are very complex, including a time-varying Lorentz force and pressure pulsation, because an induction EM pump has time-varying magnetic fields and the induced convective currents that originate from the flow of the liquid metal. These phenomena lead to an instability problem in the pump arising from the changes of the generated Lorentz forces along the pump's geometry. Therefore, a magneto-hydro-dynamics (MHD) analysis is required for the design and operation of a linear induction EM pump. We have developed a time-harmonic 2-dimensional axisymmetry MHD analysis method based on the Maxwell equations. This paper describes the analysis and numerical method for obtaining solutions for some MHD parameters in an induction EM pump. Experimental test results obtained from an induction EM pump of CLIP-150 at the STC "Sintez," D.V. Efremov Institute of Electro-physical Apparatus in St. Petersburg were used to validate the method. In addition, we investigated some characteristics of a linear induction EM pump, such as the effect of the convective current and the double supply frequency (DSF) pressure pulsation. This simple model overestimated the convective eddy current generated from the sodium flow in the pump channel; however, it had a similar tendency for the measured data of the pump performance through a comparison with the experimental data. Considering its simplicity, it could be a base model for designing an EM pump and for evaluating the MHD flow in an EM pump.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.95-101
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• 2002

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a sin91e pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents. Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found within a sump of pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface due to different clearances from back-wall to vertical intake pipe with bell mouse and without. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.209-215
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• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the Pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• 한국진공학회지
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• 제12권2호
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• pp.93-104
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• 2003

저진공펌프의 내구성평가와 관련하여 펌프의 성능이나 상태의 저하에 관한 기술적 근거를 확보함으로써 펌프의 운전상태를 진단할 수 있는 기초기술을 확보할 수 있으며, 이는 진공펌프의 기계적 결함 및 성능평가 장치의 동적 응답과 신뢰도 구축에 중점을 두고 신호 분석을 통하여 실험적으로 기계적인 동적 특성을 확인하는 과정을 통하여 수행할 수 있다. 저진공펌프의 압축일에 소요되는 전력을 이론적으로 규명하고 펌프의 압축일을 계산하였으며, 소비전력에 대한 진공펌프의 에너지 효율을 예측하여 펌프 노화에 따르는 소비전력의 증가 원인을 규명하는 자료로 활용할 수 있다. 또한 저진공펌프의 가동 중에 측정한 진동, 압력신호, 배기속도 및 소비전력을 측정하고 분석하여 펌프 운전상태를 감시하는데 매우 유용한 인자가 무엇인지 확인하였으며 추후 연구의 방향과 내구성평가의 기초기술을 확보하였다.