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  • Title/Summary/Keyword: 유도 임펠러

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A Study for the Performance Improvement of the Main Lubrication Oil Pump (선박용 주 윤활유 펌프의 성능 개선에 대한 연구)

  • Kim, Jin-Young;Chung, Kyung-Nam;Kim, Ju-Baek;Yang, Han-Jo;Lim, Shin-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.660-664
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    • 2004
  • The flow fields of a lubrication oil pump has been simulated by using CFD in order to improve performance of the pump. The grid for the one flow passage is applied for estimating pump performance. The calculation result shows that there are unfavorable flow characteristics of flow recirculation in the casing part by the guide vane. Thus, the guide vane is modified to reduce the recirculation region. Performance test shows that the modified model pump efficiency is increased by 6% at the rated point compared to that of the original model.

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Unstable Flow in a Vaneless Diffuser of 2-Dimensional Centrifugal Compressor (2차원 원심 압축기의 깃 없는 디퓨저에서의 불안정 유동)

  • Kang, Kyung-Jun;Shin, You-Hwan;Kim, Kwang-Ho;Lee, Yoon-Pyo
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.4
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    • pp.5-11
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    • 2011
  • This study investigated on details of flow characteristics in a vaneless diffuser of a compressor with 2-dimensional impeller at various flow rates. Experiment for a low speed compressor model in a water reservoir was performed to analyze the flow field in the vaneless diffuser and volute casing, which was done by PIV measurement. It was also focused on the periodic flow patterns occurring at low flow rate near unstable operating region of the compressor. At low flow rate condition, the flow visualization clearly shows that the flow energy from impeller is highly accumulated at the compressor exit by the blockage effect of a flow damper and consequently the reverse flow occurs in the diffuser.

Effect of the Passage Area Ratio of an Impeller on the Performance of Two-Dimensional Centrifugal Compressors (임펠러의 유로 면적비가 2차원 원심압축기의 성능에 미치는 영향)

  • Park, Han-Young;Shin, You-Hwan;Choi, Hang-Cheol;Kim, Kwang-Ho;Chung, Jin-Taek
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.5
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    • pp.22-29
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    • 2008
  • This study is performed to understand the effect of the variation in the passage area of a two-dimensional impeller on its performance characteristics. We observe the results with changing the area ratio of inlet to outlet about 12.8. A comparison between the experimental and numerical results was performed for the same configuration in order to verify the reliability of the CFD code. Overall characteristics in the passages of impeller were analyzed in detail including streamline, Mach number, pressure and polytropic efficiency distribution. When the passage area ratio exceeds 2, the pressure ratio is high. An area ratio of 2.3 showed the highest efficiency. The results will be used as useful reference data to establish the design concept of two-dimensional impeller and to improve its performance.

Identification on the Three-Dimensional Vortical Structures of Impeller Flow by a Multi-Plane Stereoscopic PIV Method (스테레오 PIV 기법에 의한 임펠러 와류유동의 3차원 구조측정)

  • Yoon, Sang-Youl;Kim, Kyung-Chun
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.690-695
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    • 2001
  • The three-dimensional spatial structures of impeller flow created by a six bladed Rushton turbine have identified based on the volumetric velocity information from multi-plane stereoscopic PIV measurements. A total of 10 planes with 2 mm space with a 50 mm by 64 mm size of the field of view were targeted. To reduce the depth of focus, we adopted an angle offset configuration which satisfied the Scheimpflug condition. The distortion compensation procedure was utilized during the in situ calibration. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D, volumetric velocity fields on a 60 degree sector of a cylindrical ring volume enclosing the turbine blade. Using the equi-vorticity surface rendering, the spatial structure of the trailing vortices was clearly demonstrated. Detail flow characteristics of the radial jet reported in previous studies of mixer flows were easily identified.

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미생물유래 Transglutaminase의 생산을 위한 생물반응기 운전 조건 확립

  • Lee, Hwa-Jeong;Yu, Jae-Su;Jeon, Gye-Taek;Jeong, Yong-Seop
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.239-242
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    • 2000
  • Experimental studies on the effects of impeller to provide the microbial transglutaminase derived from Streptoverticillium mobaraense have been conducted. The optimal production medium was determined by latin-square design, and the effects of aeration and agitation were observed by using different sizes and shapes of impellers for the poduction of transglutaminase. The effects of pH and temperature were also evaluated for the production of transglutaminase in flasks. As a result, pH is more effective than temperature for both enzyme production and growth of the microorganism. The peak enzyme activity for transglutaminase in fermenter was 0.7 U/mL, but this was still well below the avereage enzyme activity, 1,3 U/mL, obtained in flask runs.

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Axial Thrust Measurement of Fuel Pump for 75-ton Class Rocket Engine (75톤급 로켓엔진용 연료펌프의 축추력 측정)

  • Kim, Dae-Jin;Hong, Soon-Sam;Choi, Chang-Ho;Kim, Jin-Han
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.8-13
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    • 2010
  • An effective control of the axial thrust of a turbopump is one of the critical issues for obtaining its operational stability. Axial thrusts of the fuel pump for the 75-ton class rocket engine under development were measured with water as a test propellant at a room temperature. According to the test results, the axial thrust of the fuel pump seemed to satisfy the axial force condition of its bearing. Also, the thrust was increased as a whole when the flowrate of the pump was decreased. Furthermore it was found that the thrust and the leakage flowate were modified when the gaps between the floating ring seals and the impeller were changed.

Design of Energy Dissipaters for Improving on Efficiency in Settling Basin (침사지 효율성 제고를 위한 에너지 소산 구조물의 설계)

  • Jung, Sang-Hwa;Kim, Chang-Wan;Lee, Min-Ho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1323-1327
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    • 2006
  • 일반적으로 화력발전소는 원활한 원료 및 냉각수의 공급과 환경적인 요인으로 인해 내륙보다는 해안에 위치하고 있다. 발전소의 안정성을 확보하기 위해서는 고열의 발전기를 냉각하는 냉각설비들이 반드시 필요하며 이를 위해 취수로를 통한 냉각수의 원활한 공급이 이루어져야 한다. 이러한 냉각수 공급은 대용량 펌프에 의해 이루어지며, 취수로 구조물의 형상 및 냉각수의 흐름조건에 따라 성능과 수명이 좌우된다. 특히 해안에 위치하는 지리적 여건상 직접취수가 많으며 이러한 경우 유사가 취수로에 유입되어 펌프 흡입 시 균열과 임펠러 마모 등을 유발시켜 펌프의 안전에 악영향을 미치게 된다. 따라서 취수로에 유사의 퇴적을 유도하는 침사지를 설계하게 되며 Hydraulic Institute Standards(1998)에서는 허용설계유속을 0.2 m/s 이하로 정하고 있다. B 발전소는 직경 3 m의 대형 취수관로 3개를 통해 매우 빠른 유속으로 취수로에 유입되는 냉각수 계통 구조물을 가지고 있어 침사지 내 유속이 허용기준을 초과하였다. 본 연구에서는 침사지내 유속을 만족시키기 위해 다양한 에너지 소산 구조물 설계방안을 제시하였다. 각 설계방안에 따른 흐름 특성 및 유속 분포를 파악하고 common bay 내에서의 난류특성을 분석하여 비교.검토하였다. 수리모형실험 결과를 통해 각각의 설계방안에 따른 침사지의 효율을 평가하였으며 최적의 에너지 소산 구조물에 대한 설계방안을 제안하였다.

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Identification on the Three-Dimensional Vortical Structures of Impeller Flow by a Multi-Plane Stereoscopic PIV Method (스테레오 PIV 기법에 의한 임펠러 와류유동의 3차원 구조측정)

  • Yoon, Sang-Youl;Kim, Kyung-Chun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.6
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    • pp.773-780
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    • 2003
  • The three-dimensional spatial structures of impeller flow created by a six bladed Rushton turbine have identified based on the volumetric velocity information from multi-plane stereoscopic PIV measurements. A total of 10 planes with 2 mm space and a 50 mm by 64 mm size of the field of view were targeted. To reduce the depth of focus, we adopted an angle offset configuration which satisfied the Scheimpflug condition. The distortion compensation procedure was utilized during the in situ calibration. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D. volumetric velocity fields on a 60 degree sector of a cylindrical ring volume enclosing the turbine blade. Using the equi-vorticity surface rendering, the spatial structure of the trailing vortices was clearly demonstrated. Detail flow characteristics of the radial jet reported in previous studies of mixer flows were easily identified.

Performance Characteristic of a Pipe Type Centrifugal Pump (파이프형 원심펌프의 성능특성에 관한 실험적 연구)

  • Yu, HyeonJu;Kang, Shin-Hyoung
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.5
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    • pp.32-36
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    • 2012
  • The positive displacement pump and the regenerative pump are widely used in the range of low specific speed, ns100[rpm, m3/min, m]. The positive displacement pump is not suitable for miniaturization and operation in high rotational speed. The regenerative pump has a problem with large leakage flow and low efficiency. While the centrifugal pump has advantages of high efficiency, miniaturization and high rotational speed, efficiency drops sharply with decrease in specific speed. Therefore the purpose of this study is to design a new type of centrifugal pump that has advantages of centrifugal pumps in operation in low specific speed. The name of this new type of pump was called 'Pipe type centrifugal pump', since the flow path through the impeller is simple circular pipe. Due to the simple shape of impeller, the manufacturing process is simple and cost is low. There is strong jet flow at the outlet of the impeller. This jet induces flow path loss, meridional dynamic pressure loss and mixing loss. Large disk friction makes the efficiency be limitted in the range of low specific speed. Even though the loss and the low efficiency, 'Pipe type centrifugal pump' represents stable performance, affordable pressure ratio and efficiency better than that of other low specific speed pumps.

A Study on the Internal Flow Characteristics of a Very Low Specific Speed Centrifugal Pump by PTV (PTV 계측법에 의한 극저비속도 원심펌프의 내부유동특성에 관한 연구)

  • Choi, Young-Do;Matsui, Jun;Kurokawa, Junichi;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.1 s.34
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    • pp.9-18
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    • 2006
  • In the range of very low specific speed (ns<0.25, non-dimensional), the performance of a centrifugal pump is much different from that of a centrifugal pump of normal ns and the efficiency of the pump drops rapidly with the decrease of ns. In order to examine the reason of unstable performance characteristics of the very low ns- centrifugal pump, the internal flow of the pump with a semi-open impeller is measured by a PTV(Particle Tracking Velocimetry) system. The purpose of this study is to make clear the internal flow characteristics and to obtain basic knowledge of the pump performance. The results show that the leakage flow through tip clearance give a strong effect on the flow pattern of impeller passage. A large vortex in the impeller passage and a strong reverse flow at impeller outlet are formed in the range of small flow rates, and the vortex and the reverse flow together reduce the absolute tangential velocity at the impeller outlet and cause the performance instability.