• Title/Summary/Keyword: pipe pressure

Search Result 1,403, Processing Time 0.026 seconds

A Safety about the Pipe Joint with Nonlinear Property (비선형 특성을 갖는 파이프 연결부에 대한 안전성)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.6 no.2
    • /
    • pp.3-8
    • /
    • 2007
  • Nonlinear property and contact matter are analyzed about the pipe applied with internal pressure through this study. The weakest part and its safety can be examined. Maximum equivalent stress is shown at the contact surface between bolt and nut. The value of contact stress with the pressure of 12MPa is increased 1.4 times as large as that with no pressure. The maximum contact pressure is shown at the clamp corner of the external surface on pipe. The value of contact pressure with the pressure of 12MPa is increased 1.4 times as large as that with no pressure. The radial deformation with no pressure is also increased greatly at the middle part of internal surface on pipe. But this maximum deformation on pipe with the pressure of 12MPa is shown at the part far away the support of pipe. This value is increased 5.7 times as large as that value with no pressure. As contact status, the sticking occurs most at the external surface of pipe. It also tends to occur at the contact surface between bolt and nut. At the external surface of pipe, the sticking in case of the pressure of 12MPa occurs more than that in case of no pressure.

  • PDF

Behavior of Lateral Earth Pressure around the Underpass Constructed by the STS Construction Method

  • Jin, Kyu-Nam;Kim, Hyo-Jin;Sim, Young-Jong
    • Land and Housing Review
    • /
    • v.7 no.4
    • /
    • pp.271-279
    • /
    • 2016
  • Recently developed trenchless construction methods ensure stability for the ground settlement by inserting steel pipes along the underpass section and integrating steel pipes before ground excavation to form pipe-roof. This study is to confirm the reinforcing effect of pipe-roof by measuring lateral earth pressure acting on the underpass constructed by the STS (Steel Tube Slab) construction method. For this purpose, lateral earth pressure was measured at the left and right side of the pipe-roof after installing earth pressure cells. As a result, lateral earth pressure was measured with considerable reduction because the integrated pipe-roof shared surcharge. Therefore, economic design for the underpass could be expected by sharing design load by pipe-roof. In addition, construction cost was analyzed according to the design-load sharing ratio by pipe-roof. As pipe-roof shares design load by 40%, the total construction cost can decrease by almost 10% in the case of four-lane underpass.

Evaluation of Pressure Drop in a Circular Pipe of Refuse Collecting System (쓰레기 관로이송 시스템에서의 관로 압력손실 평가)

  • Kim, Dong-Woo;Jang, Choon-Man
    • Proceedings of the KSME Conference
    • /
    • 2007.05b
    • /
    • pp.2615-2620
    • /
    • 2007
  • This paper describes on pressure drop in a circular pipe of refuse collecting system. The flow characteristics inside the circular pipe are analyzed by three-dimensional Navier-Stokes analysis. In numerical analysis, an organic waste is modeled using the data obtained by site survey. Pressure drop obtained by numerical simulation is compared to the value obtained by experimental measurements for the two kinds of pipe; straight and bended type. The pressure drop obtained by numerical simulation has a good agreement with that of experiments. It is noted that the accurate prediction of pressure drop in the waste pipe is very important to determine the performance of turbo blower used in making a suction pressure in the waste pipe. Especially, the pressure drop for an organic waste is analyzed according to the mass flow rate of waste.

  • PDF

Fundamental stuyd on reflection phenomenon of weak pressure-wave from an open end of a pipe (관단으로부터 미소 압력파의 반사에 관한 기초적 연구)

  • Kim, Hui-Dong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.22 no.5
    • /
    • pp.618-626
    • /
    • 1998
  • This paper describes a series of fundamental studies on reflection and emission of weak pressure waves from an open end of a pipe. Acoustical theories which have been employed in the plane pressure waves inside a pipe are applied to the present study. The objective of the present study is to investigate the reflection or emission coefficient of pressure wave at an open end of a pipe, the length of open end correction, and the directivity characteristics of the pressure waves emitted from the pipe. The results show that the reflection coefficient of pressure wave at an open end and the length of open end correction decrease for the wave length of pressure wave to increase. It is also found that the reflection coefficient for a baffle plate at the exit of pipe is larger than that for no baffle plate.

Pressure Variations in Intake and Exhaust Manifold of a Single Cylinder Engine (단기통 엔진의 흡.배기계의 압력 변동에 관한 연구)

  • Choi, Seuk-Cheun;Lee, Young-Hun;Lee, Sang-Chul;Chung, Han-Shik;Lee, Kwang-Young;Jeong, Hyo-Min
    • Proceedings of the KSME Conference
    • /
    • 2003.11a
    • /
    • pp.775-780
    • /
    • 2003
  • In this study, a computer analysis has been developed for predicting the pipe pressure of the intake and exhaust manifold in a single cylinder engine. To get the boundary conditions for a numerical analysis, one dimensional and unsteady gas dynamic calculation is performed by using the MOC(Method Of Characteristic). The main numerical parameters are the variation of the exhaust pipe diameters to calculate the pulsating flow when the intake and exhaust valves are working. As the results of numerical analysis, the shapes and distributions of the exhaust pipe pressures were influenced strongly on the cylinder pressure. As the exhaust pipe diameter is decreased, the amplitude of exhaust pressure is large and the cylinder pressure was showed low in the region of intake valve opening time.

  • PDF

Evaluation of the Burst Pressure for Rectangular Wall-thinning of CANDU Feeder Pipe (사각 감육을 고려한 중수로 공급자관 파열압력 평가)

  • Kwang Soo Kim;Min Kyu Kim;Doo Ho Cho;Jae Joon Jeong
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.17 no.1
    • /
    • pp.28-35
    • /
    • 2021
  • The flow accelerated corrosion (FAC) is one of significant aging and degradation mechanism and can affect structural integrity of CANDU feeder pipes. Pipe burst can occur under normal operation pressure (min. 10 MPa) if wall-thinning of the feeder pipe due to FAC is accumulated. Previous studies considered simple shapes of feeder pipe with local wall-thinning in order to conservatively assess structural integrity of wall-thinned feeder pipe. In this paper, a new FE model is developed, having an actual shape of the feeder pipe (double bent) as well as the actual wall-thinning shape and location based on the in-service inspection result. Then, the burst pressure assessment of the wall-thinned feeder pipe is performed using lower bound limit load analysis considering elastic-perfectly plastic material. In addition, an improved formulation to predict the burst pressure of the wall-thinned feeder pipe is presented and the safety margin is compared with an existing assessment method.

Numerical investigation on the flow noise reduction due to curved pipe based on wavenumber-frequency analysis in pressure relief valve pipe system (감압 밸브 배관 시스템 내 파수-주파수 분석을 통한 곡관의 유동소음 저감에 대한 수치적 연구)

  • Garam, Ku;Cheolung, Cheong
    • The Journal of the Acoustical Society of Korea
    • /
    • v.41 no.6
    • /
    • pp.705-712
    • /
    • 2022
  • A sudden pressure drop caused by the pressure relief valve acts as a strong noise source and propagates the compressible pressure fluctuation along the pipe wall, which becomes a excitation source of Acoustic Induced Vibration (AIV). Therefore, in this study, the numerical methodology is developed to evaluate the reduction effect of compressible pressure fluctuation due to curved pipe in the pressure relief valve system. To describe the acoustic wave caused by density fluctuation, unsteady compressible Large Eddy Simulation (LES) technique, which is high accuracy numerical method, Smagorinsky-Lilly subgrid scale model is applied. Wavenumber-frequency analysis is performed to extract the compressible pressure fluctuation component, which is propagated along the pipe, from the flow field, and it is based on the wall pressure on the upstream and downstream pipe from the curved pipe. It is shown that the plane wave and the 1st mode component in radial direction are dominant along the downstream direction, and the overall acoustic power was reduced by 3 dB through the curved pipe. From these results, the noise reduction effect caused by curved pipe is confirmed.

Experimental Study of Characteristics on Double Heat Exchange Pipe Used Separation Type Air-Conditioner (분리형 에어컨용 2중 열교환 배관 특성에 관한 실험적 연구)

  • Kim, J.D.
    • Journal of Power System Engineering
    • /
    • v.10 no.4
    • /
    • pp.31-37
    • /
    • 2006
  • In this study, the ability for the function of double pipe inserted liquid pipe with small diameter in the gas pipe with large diameter for the circulating of liquid of high temperature and high pressure and low temperature and low pressure at the same time is presented. And in this double pipe, liquid pipe of high temperature and pressure is used to connect condenser and expansion valve and gas pipe of low temperature is used to connect evaporator and compressor. Also, when liquid refrigerant of high temperature and gas refrigerant of low temperature is circulated by reversed flow in the double pipe. The contribution of liquid gas heat exchange pipe is studied by comparison of the effect of heat transfer by temperature difference when liquid pipe and gas pipe is installed separately.

  • PDF

Characteristics the Pressure Variations according to the Exhaust Pipe of 4-Stroke Single Engine (4행정 단기통 엔진의 배기관에 따른 압력 변동 특성)

  • Lee, Hyo-Deok;Choi, Seok-Cheun;Lee, Sang-Chul;Lee, Kwang-Young;Jeong, Hyo-Min;Chung, Han-Shik
    • Proceedings of the KSME Conference
    • /
    • 2004.04a
    • /
    • pp.1666-1671
    • /
    • 2004
  • In this study, a experimental method has been introduced for the various exhaust pipe geometry of 4-stroke single engine. The main experimental parameters are the variation of exhaust pipe diameters and lengths, to measuring the pulsating flow when the intake and exhaust valves are working, As the results of experimental test, the various exhaust geometry were influenced strongly on the exhaust pressure. As the exhaust pipe diameter was decreased, the amplitude and the number of compression wave in exhaust pressure was increased. According to decreasing pipe diameter, the number of compression wave in exhaust pressure was decreased. When the pipe diameter was increase, the second amplitude was increased.

  • PDF

Analysis of hydraulic system for seawater desalination plant through piping analysis program (배관 해석 프로그램을 통한 해수담수화 플랜트 수압 시스템 분석)

  • Choi, Jihyeok;Choi, Yongjun;Yang, Heungsik;Lee, Sangho;Choi, June-Seok
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.34 no.3
    • /
    • pp.221-230
    • /
    • 2020
  • In actual seawater desalination plant, the pressure loss due to frictional force of pipe is about 3~5 bar. Also, the pressure loss at pipe connection about 1~3 bar. Therefore, the total pressure loss in the pipe is expected to be about 4~8 bar, which translates into 0.111 to 0.222 kWh/㎥ of energy when converted into the Specific Energy Consumption(SEC). Reducing energy consumption is the most important factor in ensuring the economics of seawater desalination processes, but pressure loss in piping is often not considered in plant design. It is difficult to prevent pressure loss due to friction inside the pipe, but pressure loss at the pipe connection can be reduced by proper pipe design. In this study, seawater desalination plant piping analysis was performed using a commercial network program. The pressure loss and SEC for each case were calculated and compared by seawater desalination plant size.