• Title/Summary/Keyword: fluid intake

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Effect of Intake Vortex Occurrence on the Performance of an Axial Hydraulic Turbine in Sihwa-Lake Tidal Power Plant, Korea

  • Kim, Jin-Hyuk;Heo, Man-Woong;Cha, Kyung-Hun;Kim, Kwang-Yong;Tac, Se-Wyan;Cho, Yong;Hwang, Jae-Chun;Collins, Maria
    • International Journal of Fluid Machinery and Systems
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    • v.5 no.4
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    • pp.174-179
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    • 2012
  • A numerical study to investigate the effect of intake vortex occurrence on the performance of an axial hydraulic turbine for generating tidal power energy in Sihwa-lake tidal power plant, Korea, is performed. Numerical analysis of the flow through an sxial hydraulic turbine is carried out by solving three-dimensional Reynolds-averaged Navier-Stokes dquations with the shear stress transport turbulence model. In the real turbine operation, the vortex flows are occurred in both the side corners around the intake of an axial hydraulic turbine due to the interaction between the inflow angle of water and intake structure. To analyze these vortex phenomena and to evaluate their impacts on the turbine performance, the internal flow fields of the axial hydraulic turbines with the different inflow angles are compared with their performances. As the results of numerical analysis, the vortex flows do not directly affect the turbine performance.

Conservation for the Seismic Models of Intake Tower with Nonlinear Behaviors and Fluid Structure Interaction (비선형거동과 구조물유체상호작용을 고려한 취수탑 내진모델의 보수성평가)

  • Lee, Gye-Hee;Lee, Myoung-Kyu;Hong, Kwan-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.17-24
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    • 2020
  • In this study, series of nonlinear seismic analysis were performed on a reinforced concrete intake tower surrounded by water. To consider the fluid effect around the structure, analysis models were composed using an added mass and CEL approach. At this time, the implicit method was used for the added mass model, and the explicit method was used for the fluid structure interaction model. The input motions were scaled to correspond to 500, 1000, and 2400 years return period of the same artificial earthquake. To estimate the counteractivity of the fluid coupled model, models without fluid effect were constructed and used as a reference. The material models of concrete and reinforcement were selected to consider the nonlinear behavior after yielding, and analysis were performed by ABAQUS. As results, in the acceleration response spectrum of the structure, it was found that the influence of the surrounding fluid reducing the peak frequency and magnitude corresponding to the fundamental frequency of the structure. However, the added mass model did not affect the peak value corresponding to the higher mode. The sectional moments were increased significantly in the case of the added mass model than those of the reference model. Especially, this amplification occurred largely for a small-sized earthquake response in which linear behavior is dominant. In the fluid structure interaction model, the sectional moment with a low frequency component amplifies compared to that of the reference model, but the sectional moment with a high requency component was not amplified. Based in these results, it was evaluated that the counteractivity of the additive mass model was greater than that of the fluid structure interaction model.

Identification of Nursing Diagnosis-Outcome-Intervention (NANDA-NOC-NIC) Linkages in Surgical Nursing Unit (일반외과 입원 환자에 적용되는 간호진단-간호결과-간호중재 연계 확인)

  • Lee, Eun-Ju;Choi, Soon-Hee
    • Korean Journal of Adult Nursing
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    • v.23 no.2
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    • pp.180-188
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    • 2011
  • Purpose: This study was to identify nursing diagnosis-outcome-intervention (NANDA- NOC-NIC: NNN) linkages applied to inpatients in general surgical nursing units. Methods: We developed the NNN linkage computerized nursing process program, which consisted of the 107 nursing outcomes and the 190 nursing interventions linked to the 39 nursing diagnoses. This program was applied to 324 patients who admitted to those nursing units from July, 2004 to February, 2005. Results: First, nursing outcomes of each nursing diagnosis were identified as follows: for 'acute pain', pain control, pain level, and comfort level; for 'risk for infection', wound healing: primary intention, wound healing: secondary intention, and infection status; for 'nausea', nutritional status: food & fluid intake, comfort level, symptom severity and hydration. Second, major nursing interventions for each nursing outcome were analyzed as follows: for pain control or comfort level, pain management and medication management; for pain level, pain management and analgesic administration; for wound healing: primary intention, incision site care and wound care; for Wound healing: secondary intention or infection status, infection control; for nutritional status: food & fluid intake, fluid monitoring; for comfort level, nausea management; for symptom severity, nausea management and vomiting management; for hydration, fluid/electrolyte management. Conclusion: This identified NNN linkages will facilitate the use of nursing process in surgical nursing practice and documentation systems.

The Effect of Pump Intake Leaning Angle and Flow Rate on the Internal Flow of Pump Sump

  • Lee, Youngbum;Kim, Kyung-Yup;Chen, Zhenmu;Choi, Young-Do
    • The KSFM Journal of Fluid Machinery
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    • v.20 no.1
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    • pp.74-80
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    • 2017
  • Pump sump system or pumping stations are built to draw water from a source such as river and used for irrigation, thermal power plants etc. If pump sump is improperly shaped or sized, air entraining vortices or submerged vortices may develop. This may greatly affect pump operation if vortices grow to an appreciable extent. Moreover, the noise and vibration of the pump can be increased by the remaining of vortices in the pump flow passage. Therefore, the vortices in the pump flow passage have to be reduced for a good performance of pump sump station. In this study, the effect of pump intake leaning angle and flow rate on the pump sump internal flow has been investigated. There are three cases with different leaning angle. Moreover, a pipe type with elbow also has been studied. The flow rate with three classes of air entraining vortices has been examined and investigated by decreasing the water level. The result shows that the air entraining vortices easily occurs at the pump intake with large leaning angle. Moreover, the elbow type of the pump intake easily occurs air entraining vortices at the high flow rate (or velocity) in comparison to other pump intake type.

The Analysis of Vibration with Pump and Pipe for Intake Station (취수장용 펌프 및 배관 진동 분석 사례)

  • Choi, B.K.;Choe, C.R.;Kim, H.J.;Gu, D.S.;Jung, H.Y.
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.200-204
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    • 2005
  • A few intake stations have vibration problems caused by pumps, motors and pipes. The vibration transffered from pumps, motors and pipes excites buiding severely. Therefore, the crack is generated on building wall and people who work at intake station are damaged. In this paper, the vibration and noise have been measured and analyzed for pumps, motors, pipes and building at intake station. Also, the cause of vibration and noise is identified. Finally, the reference of vibration and noise is established using results of measurement.

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An Efficient Fluid-Thermal Integrated Analysis for Air-Intake Structure Design of a High Speed Air Vehicle (고속 비행체 공기흡입관 구조설계를 위한 효율적 유체-열 통합해석 연구)

  • Chun, Hyung-Geun;Ryu, Dong-Guk;Lee, Jae-Woo;Kim, Sang-Ho
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.23 no.3
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    • pp.8-17
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    • 2015
  • In this research, low fidelity air/heat load analysis was conducted for the intake of high speed vehicle. For air/heat load calculations, aerodynamic properties at the surface and the boundary layer edge were estimated using Taylor-Maccoll equation for conical flow, shockwave relation and Prandtl-Meyer expansion equation for internal and external flow. Couette flow assumption and Reynolds analogy were used in order to calculate convective heat transfer coefficient. In order to calculate skin friction coefficient for heat transfer coefficient analysis, Van Driest method II and Reference Enthalpy method were considered. An axis symmetric SCRAMJET model was selected as a reference configuration for verifying the proper implementation of the present method. Comparison of the results using the present method and Computational Fluid Dynamic analysis showed that the present method is valuable for efficiently providing pressure and heat loads for air-intake structure design of the high speed air vehicle.

Case-Control Study of Diet and Prostate Cancer in a Rural Population of Faisalabad, Pakistan

  • Bashir, Muhammad Naeem;Malik, Muhammad Akram
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.6
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    • pp.2375-2378
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    • 2015
  • Background: The effects of diet on epidemiology of prostate cancer are inconclusive. Therefore a hospitalbased, case-control study was conducted in a rural population of Faisalabad, Pakistan, to examine the impact of dietary factors on risk of cancer development. Materials and Methods: This study was based on 102 confirmed cases of prostate cancer and 204 normal controls. Logistic regression was used to estimate odds ratios and 95% confidence intervals for odds ratios to evaluate the relationship between prostate cancer and diet. Results: Consumption of red meat and fat items significantly increased the prostate cancer risk having odds ratios and 95% confidence intervals of 3.41; 1.46-7.96 and 2.45; 1.17-5.15, respectively. On the other hand, more consumption of vegetables, fluid intake and fruit significantly decreased the prostate cancer risk (odd ratios and corresponding 95% confidence intervals of 0.21; 0.10-0.44, 0.10; 0.05- 0.19 and 0.09; 0.03- 0.23, respectively. Conclusions: The present study supports the hypothesis that frequent consumption of red meat and fat items may increase prostate cancer risk while more intake of fruit, vegetables and fluid intake may protect against prostate cancer in the relatively low risk group in rural Pakistan.

Waterhammer for the Intake Pumping Station with the Pump Control Valve (펌프제어밸브를 사용한 취수펌프장에서의 수격현상)

  • Kim, Kyung-Yup;Oh, Sang-Hyun
    • The KSFM Journal of Fluid Machinery
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    • v.4 no.4 s.13
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    • pp.16-21
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    • 2001
  • The field tests on the waterhammer were carried out for PalDang intake pumping station of the metropolitan water supply 5th stage project. The pumping station was equipped with the pump control valve as the main surge suppression device and the surge relief valve as auxiliary. However, the pump control valve had not been early controlled in the planned closing mode, and the slamming occurred to the valve which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. It was desirable that the surge relief valve was installed in the pumping station or near the pump exit for the delay of response. After reforming the oil dashpot of the pump control valve, the sliming disappeared and the measured pressure was in fairly good agreement with the results of simulation. In case of three pumps for ${\phi}2,600$ pipeline being simultaneously tripped, the pressure head in the pumping station increased to 95.6 m, and the upsurge caused by the emergency stop of four pumps for ${\phi}2,800$ pipeline was 89.6m. We concluded that the pumping station acquired the safety and reliability for the pressure surge.

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Hazardous Gas Detecting and Capturing Robot (유해가스 탐지·포집 로봇)

  • Shin, Juseong;Pyo, Juhyun;Lee, Meungsuk;Park, Sanghyun;Park, Seoyeon;Suh, Jinho;Jin, Maolin
    • Journal of Drive and Control
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    • v.19 no.2
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    • pp.27-35
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    • 2022
  • This study presents one man-portable, hazardous gas detecting and capturing robot. The robot can be fit in the trunk of a sedan car. Its weight is less than 20 kg. A dedicated gas intake mechanism is proposed for the robot. The robot can detect and capture gases at a height of 2 m above the ground, although the height of the robot is about 0.2 m. The performance of the gas intake mechanism is verified through computational fluid dynamics (CFD) analysis and experiments. Its gas detecting signals were acquired by serial communication and processed in Robot Operating System (ROS) based control software. The proposed robot can successfully move on rough terrains such as stairs, sand roads, and rock roads.

Establishment of reference intake of water for Korean adults in 2015 (2015 한국 성인의 수분 섭취기준 설정)

  • Lee, Jae-Hyun;Kim, Sun-Hyo
    • Journal of Nutrition and Health
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    • v.50 no.2
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    • pp.121-132
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    • 2017
  • Purpose: This review was performed to establish a reference intake of water for Korean (KDRI-water) adults in 2015 by examining current knowledge of the relationship between water intake and health and the general status of water intake and loss. We expect that this study will be utilized for further refinement of KDRI-water. Methods: Documents were searched using RISS, NDSL, DBPIA, CINAHL, and Pubmed with the keywords 'water intake, water supply, water ingestion, hydration, dehydration, water balance, and fluid balance'. Results: Water balance is essential for the maintenance of health. Based on this assumption, numerous studies have been performed to investigate the association of water intake with several diseases such as urolithasis, obesity, diabetes, and cancer as well as other health problems, including constipation, cognition, and fetal weight. Effects of water intake for prevention or relief of these health problems vary. Water is supplied to the body by eating foods and drinking liquids such as plain water and beverages. Metabolic water is another source of water input. Water is lost through urine, skin, respiration, and feces. KDRI-water 2015 was set by adequate intake (AI) based on water intake volume, which was the sum of water intakes from foods and fluids reported by the Korea National Health and Nutrition Examination Survey, with extra milk intake of 200 mL. AIs in some age groups were modified considering their estimated energy requirements. Conclusion: Accurate data of water intake is critically important for the establishment of KDRI-water. Therefore, improvement of systems investigating water intake is required, and more studies on the status of water intake and loss in Korean people are needed for definite KDRI-water establishment.