• Title/Summary/Keyword: Perforated pipe

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Design of the long perforated pipe in water treatment process using CFD (전산유체역학(CFD)를 활용한 정수공정에서 길이가 긴 유공관 설계)

  • Cho, Young-Man;Yoo, Soo-Jeon;Roh, Jae-Soon;Bin, Jae-Hoon
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.3
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    • pp.295-305
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    • 2010
  • Role of the perforated pipe is to drain the water with equal pressure and velocity through the holes of perforated pipe. The perforated pipe is being used in many processes of water treatment system, however, the design parameter of perforated pipe is not standardized in korea. In this study, we have found the design parameter of perforated pipe in the water treatment system using the Computational Fluid Dynamics (CFD). The uniformity of outflow from the perforated pipe is directly affected according to area ratio(gross area of holes/surface area of the perforated pipe). In other words, the uniformity of outflow is improved as area ratio is smaller. Also, at the same area ratio, the uniformity of outflow is improved as number of holes is increase. Specially, in case of the two holes per length of pipe diameter(2/D) shows the most uniformity of outflow and the best hydraulic with the smaller pressure drop. The uniformity of outflow is aggravated and the pressure drop of pipe is decrease as length of pipe is longer. In case of that pipe length is 10m and above, the pressure drop decreased about 30% when diameter ratio is 40% with 0.2% of area ratio by comparison with 0.1% of area ratio.

An Experimental Study on the Impulse Noise Emitted from the Exit of a Perforated Pipe (다공관 출구로부터 방사된 충격성 소음에 관한 실험적 연구)

  • Heo, Sung-Wook;Je, Hyun-Su;Yang, Soo-Young;Lee, Dong-Hoon
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.2066-2070
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    • 2003
  • This experimental study describes the propagation characteristics and suppression of the impulse noise emitted from the exit of a perforated pipe attached to the open end of a simple shock tube. The experiment is performed through the systematic change of the shock wave Mach number and the geometrical parameters such as the porosity, hole diameter and length of the perforated pipe. The experimental results for the near and far sound field are presented and explained in comparison with those for a straight pipe. The results obtained show that for the near sound field the impulse noise strongly propagates toward to the pipe axis, but for the far sound field the impulse noise uniformly propagates toward to the all directions, indicating that the directivity pattern is almost same regardless of the pipe type. Moreover, the noise reduction performance of perforated pipe depends upon the condition of sound field. For the near sound field the perforated pipe has a little performance to suppress the impulse noise, but for the far sound field the perforated pipe has little performance to suppress the impulse noise.

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Field Application of Permeable Polymer Concrete Pipe for Drainage (집.배수용 투수성 폴리머 콘크리트 관의 농업 수리시설물의 현장적용)

  • 민정기;연규석;성찬용
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.6
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    • pp.136-143
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    • 2003
  • This study is performed to evaluate performance of the developed pipe when using for underground drainage in fm land, the efficiency of the pipe is examined such as quantity of drainage, water temperature and other field performance in all weather condition. Results of this study, the higher permeability through wall of the pipe is achieved by making various size pores using open-graded aggregate. And in all weather conditions, permeable polymer concrete pipe perform much better than conventional perforated pipes. During rice farming period, quantity of drainage the permeable polymer concrete pipe is 1.25 time greater than conventional perforated pipes. Therefore, use of the permeable polymer concrete pipe is greater advantages when considering collecting and draining capacity compared with conventional perforated pipes.

A Study of the Impulse Wave Discharged from a Perforated Pipe (다공관으로부터 방출되는 펄스파에 관한 연구)

  • Shin Hyun Dong;Kweon Yong Hun;Kim Heuy Dong
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.95-98
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    • 2003
  • When a shock wave discharges from an open end of a duct, an impulse wave is generated outside the duct, causing serious noise and vibration problems. The magnitude of the impulse wave can be reduced by installing of a perforated duct. In the current study, the characteristics of the impulse wave discharged from the exit of a perforated duct are numerically investigated. A TVD (total variation diminishing) scheme is used to solve the unsteady, axisymmetric, compressible Euler equations. In computations, the porosity of a perforated pipe $(\sigma)$ and the Mach number of incident shock wave $(M_s)$ are varied in the range of $\sigma=0\~19\%\;and\;M_s=1.01\~1.50$, respectively. The results show that the directivity and magnitude of impulse wave strongly depend upon the Mach number of incident shock wave and the porosity of the perforated pipe. The present CFD results are in close agreement with experimental results.

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Design of the Perforated Pipe in Water Treatment Process using CFD (전산유체역학(CFD)를 활용한 정수공정에서 유공관 설계)

  • Cho, Young-Man;Yoo, Soo-Jeon;Roh, Jae-Soon;Bin, Jae-Hoon
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.9
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    • pp.887-893
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    • 2010
  • Role of the perforated pipe is to drain the water with equal pressure and velocity through the holes of perforated pipe. The perforated pipe is being used in many processes of water treatment system, however, the design parameter of perforated pipe is not standardized in korea. In this study, we have found the design parameter of perforated pipe in the water treatment system using the Computational Fluid Dynamics (CFD). The uniformity of outflow from the perforated pipe is directly affected according to area ratio (gross area of holes/surface area of the perforated pipe). In other words, the uniformity of outflow is improved as area ratio is smaller. Also, at the same area ratio, the uniformity of outflow is improved as number of holes is increase. Specially, in case of the two holes per length of pipe diameter (2/D) shows the most uniformity of outflow and the best hydraulic with the smaller pressure drop. When the inlet velocity of pipe is about 0.06m/sec, the flux of pipe has decreased as from front to backward. When the inlet velocity is 3 m/s, the flux of pipe has increased as from front to backward.

Propagation Characteristics of the Impulse Noise Emitted from the Exit of a Perforated Pipe (다공관 출구로부터 방사된 충격성 소음의 전파특성)

  • 제현수;양수영;이동훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.168-173
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    • 2003
  • This experimental study describes the propagation characteristics of the impulse noise emitted from the exit of a perforated pipe attached to the open end of a simple shock tube. The pressure amplitudes and directivities of the impulse wave propagating from the exit of perforated pipe with several different configurations are measured and analyzed fur the range of the incident shock wave Mach number between 1.02 and 1.2. In the experiments, the impulse waves are visualized by a Schlieren optical system for the purpose of investigating their propagation pattern. The results obtained show that for the near sound field the impulse noise strongly propagates toward to the pipe axis, but for the far sound field the impulse noise uniformly propagates toward to the all directions, indicating that the directivity pattern is almost same regardless of the pipe type. Moreover, it is shown that for the far sound field the perforated pipe has little performance to suppress the impulse noise.

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An Experimental Study on the Impulse Wave Discharged from the Exit of a Perforated Pipe (다공관 출구로부터 방출되는 펄스파에 관한 실험적 연구)

  • 허성욱;이동훈;김희동
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.05a
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    • pp.67-71
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    • 2003
  • The propagation characteristics of the impulse wave discharged from the exit of a perforated pipe is investigated through a simple shock tube facility. The pressure histories and directivities of the impulse wave propagating outside from the exit of pipe with several different configurations are analyzed for the range of the incident weak shock wave Mach number between 1.02 and 1.2. In the shock tube experiments, the impulse wave are visualized by a Schlieren optical system for the purpose of understanding its propagation characteristics. The experimental results show that for the near sound field the impulse noise strongly propagates toward to the pipe axis, but for the far sound field the impulse noise uniformly propagates toward to the omnidirections, indicating that the directivity pattern is almost same regardless of the pipe type. Especially, it is shown that the perforated pipe has a little performance to reduce the impulse noise only for the near sound field

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Comparative Study on the Subsurface Drainage Discharge Performance by the Type of Non-Excavation Subsurface Drainage Culvert (비굴착 지하배수암거 형태별 지하배수 성능 비교분석)

  • Kim, Hyuntai;Ryu, Jeonyong;Jung, Kiyuol;Seo, Donguk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.6
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    • pp.73-81
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    • 2018
  • In this study, subsurface discharge performance has been studied through theoretical seepage analysis on four types of culverts that can be installed under the condition of non-excavation, such as (a)perforated pipe(${\Phi}50mm$), (b)perforated pipe+horizontal mat (B50cm) (c)perforated pipe+horizontal mat+vertical gravel(B<10cm), (d)perforated pipe+vertical gravel(B<10cm), and existing typical type (e)perforated pipe with gravel (B40, h=40cm) which can be installed by excavation. The analysis results were as follows. i) Subsurface discharge performance per unit (m) was (a)type 56%, (b) 91%, (c) 96%, (d) 76%, respectively, lower than the value of (e)culvert. ii) However, considering that non-excavation culvert can be installed at a spacing of 5m with the installation cost of the existing excavation culvert at the interval of 10m, it was analyzed that unit subsurface discharge(q) of (a)20.2mm/day(110%), (b)32.8(178%), (c)34.6(188%) (d)27.5(149%) in the four types of non-excavation culvert installed at intervals of 5m under the condition of $ k=10^{-4}cm/s$ was much larger than the amount of (e)type 18.5(100%), existing excavation culvert installed at 10m interval. iii) Through the test construction, peak subsurface drainage discharge($q_p$) was 38.4mm/day, which is larger than the value of design criteria and confirmed that it satisfies the analysis results as well. iv) In particular, it was evaluated that (b)perforated pipe+horizontal mat(B50cm) are low cost, high efficiency subsurface drainage culvert type with sufficient drainage performance(178%).

Finite Element Analysis for Bending Performance of Steel Pipe Pile Cap with the Open Perforated Shear Connector (개방형 유공강판 전단연결재로 보강된 강관말뚝머리의 휨거동에 관한 유한요소 해석)

  • Kim, Young-Ho;Kang, Jae-Yoon;Yoo, Seung-Woon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.10
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    • pp.4018-4023
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    • 2010
  • Various kinds of shear connector such as headed stud, channel, perforated steel plate and others are commonly used to transfer stress and present composite performance in composite structures, and many researches have been conducted to improve the characteristics of different types of shear connectors. It is focused in this study on the bending performance of steel pipe pile cap with the open type perforated shear connector for the composite connection to the spread footing. Nonlinear analysis was conducted, using ABAQUS, a finite element analysis program, to obtain information for determining the characteristics of the structure and to allow various parametric analysis for bending performance of steel pipe pile cap with the open perforated shear connector.

The Error Involved in the Equivalent Electroacoustic Circuit Approach for the Element of Straight Pipe in Multiple Layer Perforated Plate Systems (다중 다공판 시스템에서 직관요소에 대한 전기음향등가회로법의 오류)

  • 이동훈;권영필
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.3
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    • pp.180-185
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    • 2003
  • The equivalent electroacoustic circuit approach has been conventionally used for the analysis of the multiple layer perforated plate system. However, it is found that an analogy error has been involved in the equivalent electroacoustic approach proposed by previous researchers for the element of straight pipe. Although the pipe between the perforated layers is a distributed element in the analogy, it has been treated as a parallel element by previous investigators. The analogy error is demonstrated by comparing the calculated absorption coefficients based on the parallel circuit and the distributed circuit, respectively, with the measured values by the two-microphone impedance tube method.