• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.528-533
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• 2005

This paper presents the study of flows at T-junction pipe with orifices. Experiments were carried out for several flow rates, orifice sizes, and pressure differences. Numerical simulations were also done to get more data for the wide range of flow rates. Experimental results and numerical ones are in a good agreement. Due to the effect of T-junction part, the flow rates at the lateral pipe are greater than those at straight pipe for the same pressure differences. When orifices were added, the effects of T-junction part on the ratio of flow rates and the ratio of loss coefficients reduced.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.39-44
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• 2005

This paper presents the study of flows at T-junction pipe with orifices. Experiments were carried out for several flow rates, orifice sizes, and pressure differences. Numerical simulations were also done to get more data for the wide range of flow rates. Experimental results and numerical ones are in a good agreement. Due to the effect of T-junction part, the flow rates at the lateral pipe are greater than those at straight pipe for the same pressure differences. When orifices were added, the effects of T-junction part on the ratio of flow rates and the ratio of loss coefficients reduced.

• Journal of computational fluids engineering
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• v.14 no.1
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• pp.35-44
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• 2009

To adequately analyze flows in pipe or duct network system, traditional node-based junction coupling methods require the junction loss which is specified by empirical or analytic correlations. In this paper, a new finite volume junction coupling method using a ghost junction cell is developed by considering the interchange of linear momentum as well as the important wall-effect at junction without requiring any correlation on the junction loss. Also, boundary treatment is modified to preserve the stagnation enthalpy across boundaries, such as pipe-end and the interface between junction and branch. Also, the computational accuracy and efficiency of the Godunov-type finite volume schemes are investigated by tracing the total mechanical energy of rapid transients due to sudden closure of valve at downstream end.

• Journal of Korean Institute of Industrial Engineers
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• v.10 no.2
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• pp.17-27
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• 1984

This paper is concerned with a branched pipe network system which transports some fluids or gas from multiple sources to multiple demand nodes. A nonlinear programming model is proposed for determining junction locations simultaneously with selection of pipe sizes and pump capacities such that the capital and operating costs of the system are minimized over a given planning horizon. To solve the model, a hierarchical decomposition method is developed with the junction location being the primary variable. With some values fixed for the primary, the other decision variables are found by linear programming. Then, using the postoptimality analysis of LP, junction locations are adjusted. We repeat this process until an optimum is approached. A simple example of designing a water distribution network is solved to illustrate the optimization procedure developed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.443-444
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• 2006

The influence of the heat sources on LED junction temperature are Engine room air, Back plate, Electric power device, and so on. LED lamp cooling system is considered to be an important subject fur high light efficiency. Because LED Chip will be problem When LED junction temperature be over $135^{\circ}C$, In this Study, The Looped Heat Pipe System is considered to prevent LED Chip fall. The LHPS is consist of evaporator part, condenser part, heat pipe part. The working fluid of LHPS is HCFC-123. In this study, to prevent LED Chipfall, we study thermal characteristics for Looped Heat Pipe System with LED lamp.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.855-856
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• 2009

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1813-1817
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• 2007

The present work presents plastic limit load solutions for piping branch junctions with local wall-thinning, based on detailed three-dimensional (3-D) and small strain FE limit analyses using elastic-perfectly plastic materials. Three types of loading are considered; internal pressure, in-plane bending on the branch pipe and in-plane bending on the run pipe. The wall-tinning located on variable area of the piping branch junction is considered. A wide range of piping branch junction and wall-thinning geometries are considered. Comparison of the proposed solutions with FE results shows good agreement

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.626-629
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• 2008

Numerical predictions on flow phenomena in pipe network systems have been considered as playing an important role in both designing and operating various facilities of piping or duct systems, such as water supply, tunnel or mine ventilation, hydraulic systems of automobile or aircraft, and etc. Traditionally, coupling conditions between junction and connected branches are assumed to satisfy conservation law of mass and to share an equal pressure at junction node. However, the conventional methodology cannot reflect momentum interactions between pipes sufficiently. Thus, a new finite volume junction treatment is proposed both to reflect the interchanges of linear momentums between neighbor branches at junction and to include the effect of wall at junction in present work.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.69-75
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• 2019

In recent years, the driving performance and exhaust sound quality in automobiles have been recognized as important factors, as they maximize the driving fun to fulfil the demands of customers. Therefore, many automobile manufacturers are studying various exhaust pipe shapes to improve sound quality and optimize exhaust pressure. The objective of the exhaust pipe design is to maximize the engine efficiency using optimal exhaust pressure settings. In this study, an exhaust system was fabricated with different junction shapes, and the results were analyzed through various experiments. The exhaust gas pressure acting inside the exhaust pipe was measured using a pressure transducer. Meanwhile, the vibration generated in the vehicle was measured in three axial directions and analyzed. The ground noise generated in the indoor and outdoor of the vehicle was measured, and the noise generated at the maximum output was measured and analyzed.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.101-108
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• 2000

Pipe network analysis is analyze all of it about pressure and volume flow rate through that are pipeline, junction, regulator and valve etc. In this study is compare TVD with MOC method for analysis of unsteady compressible flow in pipelines. Then, we calculated unsteady compressible flow for pipe network that periodic volume flow rate conditions.