• 제목/요약/키워드: Flow pump technique

검색결과 87건 처리시간 0.025초

유체유동에 의한 유연한 파이프의 불안정과 진동억제에 미치는 부가질량의 영향 (Effects of Attached Masses on the Instability and Vibration Suppression of a Flexible Pipe Conveying Fluid)

  • 류봉조;정승호;이종원
    • 소음진동
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    • 제10권2호
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    • pp.280-290
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    • 2000
  • The paper deals with vibration suppression and dynamic stability of a vertical cantilevered pipe conveying an internal flowing fluid and having an attached mass. Real pipe systems may have some valves or mechanical attached parts, which can be regarded as attached lumped masses. The effect of attached mass on the dynamic stability of a cantilevered pipe conveying fluid is investigated for different locations and magnitudes of the attached mass. The flow rate was controlled through motor pump output and measured by a flow meter. Experimental resutls in the vicinity of flutter fluid velocity were compared with theoretical predictions. It has been found that the experimental results are in substantial agreement with the theoretical predictions. Finally, in order to suppress the vibration of the pipe subjected to a disturbance, and control technique using an internal flowing fluid is introduced.

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PIV에 의한 원관내 Ice Slurry의 유동계측 (PIV Measurement on Ice Slurry Pipe Flow)

  • 황태규;홍성대;박성룡;백태실;도덕희
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2004년도 추계학술대회 논문집
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    • pp.98-101
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    • 2004
  • Experimental studies were reported on the characteristics of flows in a circular pipe in which ice slurry is flowing. This was mainly due to deficiency of conventional measurement techniques. In this report, the flow characteristics are quantitatively investigated by the use of PIV technique concerning the Ice Packing Factor(IPF) and the power changes of pump motor. It was experimentally verified that the power loss does not increase any more at a certain IPF value.

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PIV에 의한 원관내 Ice Slurry의 유동계측 (PIV Measurement on Ice Slurry Pipe Flow)

  • 도덕희;김동혁;오철;홍성대;박성룡;황태규
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권2호
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    • pp.177-184
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    • 2005
  • Experimental studies on the characteristics of ice slurry flows in a circular pipe is rare due to the deficiency of conventional measurement techniques. In this report the flow characteristics are quantitatively investigated by the use of PIV technique concerning the Ice Packing Factor(IPF) and the power changes of pump motor It was experimentally verified that the power loss does not increase any more at a certain IPF value.

수평원통 관에서 선회유동의 공기동 발생에 관한 실험적 연구 (An Experimental Study on the Generation of Air-core with Swirl Flow in a Horizontal Circular Tube)

  • 장태현
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권6호
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    • pp.922-930
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    • 2004
  • An experimental investigation was performed to study on the generation of air bubble and air core with swirling flow in a horizontal cicular tube. To determine some characteristics of the flow, 2D PIV technique is employed for velocity measurement in water. The experimental rig is manufactured from an acryl tube. The test tube diameter of 80mm, and a length of 3000mm. The used algorithm is the gray leve cross-correlation method(Kimura et al. 1986). An Ar-ion laser is used and the light from the laser(500mW) passes through a probe to make two-dimensional light sheet. In order to make coded images of the tracer particles on one frame, an AOM(Acoustic-Optical Modulator) is used. The maximum axial velocities showed near the test tube wall at y/D =0.1 and y/D =0.9 along the test tube. The higher Reynolds number increase, the lower axial velocities are showed in the center of the test tube. The air bubbles are generated from Re =10,000 and developed into air core from the recirculating water pump rpm equal 30Hz. The pressure and temperature are measured across the test tube at X/D=3.33.

전자기장을 이용한 준설토 고효율 이송기술 실증 및 기술 지침 개발 (Dredging Material High Efficiency Transport Technology Test by Using the Electro Magnetic Field and Development of the Technical Design Manual)

  • 김동철;김유승;여찬수;김선빈;박승민
    • 한국연안방재학회지
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    • 제5권4호
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    • pp.173-182
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    • 2018
  • As the research about increasing the efficiency of dredging soil transport, the technology, which reduce the friction between pipe wall and fluid in the pipe and disturbed generating pipe blockage, has been developed. So for the purpose of applying this technology to real construction site, main test has been tried at the real scale test in field. As a test result, this paper will show 30% flow efficiency increasing by permitted electro magnetic force to the pipe. And test result was evaluated as a ultra sonic velocity profiler. To propose the design technique and the execution manual of the high efficiency dredging material transport technic, this research have confirmed flow status changing depending on a soil material kind under electro-magnetic field and analyze the effect of electro-magnetic field which affects to each dredged soil material transportation. For achieving this research, EMF(Electro-Magnetic Field) generator is installed on the dredger(20,000HP) and through monitored flow status, dredging soil flow rate and sampled material specification is confirmed. Also dredger operating condition is measured and dredger power for soil transportation, hydraulic gradient and flow rate are compared, as transportation efficiency is calculated by this parameter, it is possible to check transportation efficiency improvement depending on each dredged soil material under electro-magnetic field. To verify the technique of dredged soil transfer using electromagnetic field, which is the core technique of the high efficiency dredged soil transfer, and the technique of expert system for pipeline transfer and the flow state. This could lead to a verification of transfer efficiency according to the characteristics of the dredged soil (sand, clay, silt) and the transfer distance (5km, 10km, 15km), which is planned to be used for a technology development of pump power reduction and long-distance transfer applying the high efficiency dredged soil transfer technology.

유체-구조 연성해석을 통한 축류펌프의 진동 연구 (A Study of the Vibration of an Axial Flow Pump through FSI Analysis Method)

  • 이보람;윤태종;오원빈;이충우;김학형;정영재;김일수
    • 한국기계가공학회지
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    • 제20권3호
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    • pp.107-112
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    • 2021
  • Pressure, which is a dynamic characteristic of a floodgate, is predicted using an FSI analysis method. A fluid analysis model and a hydrology analysis model were used as analysis models. As a result of the analysis, we found that a warped model has smaller acceleration than a square model. Additionally, this numerical analysis technique was applied to the actual hydrology, and the analysis results were compared with the results of the vibration tests. As a result, we confirmed that there is a small difference between the results of the vibration tests and the results of the FSI analysis. Through this analysis, the applicability and reliability of the FSI analysis method were verified. We concluded that the pressure of a floodgate can be measured through an FSI analysis method.

The observation of permeation grouting method as soil improvement technique with different grout flow models

  • Celik, Fatih
    • Geomechanics and Engineering
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    • 제17권4호
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    • pp.367-374
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    • 2019
  • This study concluded the results of a research on the features of cement based permeation grout, based on some important grout parameters, such as the rheological properties (yield stress and viscosity), coefficient of permeability to grout ($k_G$) and the inject ability of cement grout (N and $N_c$ assessment), which govern the performance of cement based permeation grouting in porous media. Due to the limited knowledge of these important grout parameters and other influencing factors (filtration pressure, rate and time of injection and the grout volume) used in the field work, the application of cement based permeation grouting is still largely a trial and error process in the current practice, especially in the local construction industry. It is seen possible to use simple formulas in order to select the injection parameters and to evaluate their inter-relationship, as well as to optimize injection spacing and times with respect to injection source dimensions and in-situ permeability. The validity of spherical and cylindrical flow model was not verified by any past research works covered in the literature review. Therefore, a theoretical investigation including grout flow models and significant grout parameters for the design of permeation grouting was conducted in this study. This two grout flow models were applied for three grout mixes prepared for w/c=0.75, w/c=1.00 and w/c=1.25 in this study. The relations between injection times, radius, pump pressure and flow rate for both flow models were investigated and the results were presented. Furthermore, in order to investigate these two flow model, some rheological properties of the grout mixes, particle size distribution of the cement used in this study and some geotechnical properties of the sand used in this work were defined and presented.

전산유체해석을 통한 RE엔진 냉각수 코어의 성능 개발 (Performance Development of Coolant Core for Range Extender Engine Using CFD Simulation)

  • 김창수;박성영
    • 한국산학기술학회논문지
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    • 제14권5호
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    • pp.2075-2080
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    • 2013
  • 본 논문에서는 RE엔진에 적용하기 위한 냉각수 코어를 CFD 기술을 활용하여 개발하였다. 개선 모델은 배기밸브 주위와 사이의 온도를 저감하기 위한 냉각수 우회부를 추가하였다. 2번 실린더 블록 주위와 배기밸브 사이의 유량이 증가하였기 때문에, 베이스 모델대비 개선 모델의 유량 정체가 개선되었다. 결과적으로, 배기밸브 주위에서의 열전달이 향상되고, 전 유량 구간에서 기존 모델 대비 약 5%의 압력 강하량 저감 효과를 보이는 개선 모델을 얻을 수 있었다. 압력 강하량의 저감은 상응하는 냉각수 펌프의 부하를 저감하고 연비에 긍정적 영향을 미칠 것으로 판단된다.

무선 전자식 장비를 이용한 지중열전도도 측정 기술 (Ground Thermal Conductivity Test with A Wireless Probe)

  • 김지영;이의준;장기창;강은철;고건혁
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2381-2384
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    • 2008
  • The heat exchange between the Borehole Heat Exchanger(BHE) and the surrounding ground depends directly on ground thermal conductivity k at the certain site. The k is thus a key parameter in designing BHE and coupled geothermal heat pump systems. Currently, although a thermal hydraulic Response Test(TRT) is mostly used in practice, the thermal hydraulic TRT needs additional power and is generally time-consuming. A new, simple wireless probe for hi-speed k determination was introduced in this paper. This technique using a wireless probe is less time-consuming and requires no external source of energy for measurement and predicts local thermal properties by measuring soil temperatures along the depth. Measured temperature data along the depth was analyzed. As a result, the electronic wireless probe can replace the conventional hydraulic TRT method after carrying out the additional research on a lot of local heat flow, etc.

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마이크로 레이저 형광 여기법을 이용한 미세채널 내부에서의 산소 확산에 대한 정량적 가시화 (Quantitative Visualization of Oxygen Transfer in Micro-channel using Micro-LIF Technique)

  • 천쥐안;김현동;김경천
    • 한국가시화정보학회지
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    • 제10권1호
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    • pp.34-39
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    • 2012
  • In the present study, oxygen transfer process across gas-liquid interface in a Y-shape micro-channel is quantitatively visualized using the micro laser induced fluorescence (${\mu}$-LIF) technique. Diffusion coefficient of Oxygen ($D_L$) is estimated based on the experimental results and compared to its theoretical value. Tris ruthenium (II) chloride hexahydrate was used as the oxygen quenchable fluorescent dye. A light-emitting diode (LED) with wavelength of 450 nm was used as the light source and phosphorescence images of fluorescent dye were captured by a CMOS high speed camera installed on the microscope system. Water having dissolved oxygen (DO) value of 0% and pure oxygen gas were injected into the Y-shaped microchannel by using a double loading syringe pump. In-situ pixel-by-pixel calibration was carried out to obtain Stern-Volmer plots over whole flow field. Instantaneous DO concentration fields were successfully mapped according to Stern-Volmer plots and DL was calculated as $2.0675{\times}10^{-9}\;m^2/s$.