• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.154-159
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• 2012

For numerical analysis of the plate heat exchanger, a lot of time are required in modeling work and calculation. Whereas, this paper was purposed to identify characteristic of the plate heat exchanger through simplification of modeling by interpreting the numerical analysis proximity with the actual model. This study was also examined temperature difference between inlet side and outlet side, inner pressure drop, heat transfer area of plate and change of heat transfer coefficient on the plate depending on the inner corrugation angle and corrugation pitch of a herring bon pattern of the plate heat exchanger among chevron types of the plate exchanger.

• Tribology and Lubricants
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• v.25 no.6
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• pp.374-380
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• 2009

This paper presents the stress and displacement characteristics of oil pipe using the finite element analysis. Displacement in axial direction and von Mises stress of a pipe were analyzed with three design factors, which are the pipe thickness, the corrugation pitch and the corrugation height, under uniform oil pressure. The FE computed results are presented between a conventional round pipe and a rectangular pipe, which is manufactured in this study. The computed FE results show that maximum displacement in axial direction and von Mises stress of pipe are increased linearly as the oil pressure increases. Also, they are increased linearly as the corrugation pitch, corrugation height and pipe thickness increases. von Mises stress of a rectangular pipe at the edge increases sharply compared with that of a conventional round pipe. Therefore, the strength of rectangular pipe is superior to that of a conventional round pipe.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.965-973
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• 2010

Numerical analysis has been carried out to investigate the heat transfer characteristics of a plate heat exchanger. The multi-cell models with inlet part and outlet part are used for performing numerical simulation. The plate heat exchanger is characterized by chevron angle of $15^{\circ}$, corrugation pitch of 24mm and corrugation height 6~12mm. The length of the inlet-part considered in the analysis ranges from 24.8 to 124mm and Reynolds numbers range from 1,000 to 10,000. The correlations such as friction factor and Colburn factor are compared with previous experimental data. The results can be utilized for designing the plate heat exchanger.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.109-117
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• 2022

Membrane panels are installed in LNG cargo-hold in order to endure extremely low temperature LNG. Although there are several types of membranes around the world, Korean LNG cargo containment system is developing to accomplish technology independence from the other countries. The membrane panel of Korean LNG cargo containment system is composed of corrugation and flat sheets which are arranged asymmetrically. It is very important to reduce the number of the type of corrugation sheet because a mold is required as much as the type of the corrugation sheet. Therefore, we proposed an optimization method to minimize the type of the corrugation sheet. For this method, the number of pitches, which is the distance between the centers of two corrugation sheets should be minimized. We also developed optimized arrangement procedure of the flats simultaneously. Finally, the developed optimization program is applied to 174K LNG cargo hold, and the minimum pitch size is found.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.39-43
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• 2011

In this study, the stress and deformation behavior characteristics of a flexible joint for a gas pipe have been analyzed by a finite element method. These characteristic results may investigate the strength safety analysis of a flexible joint, which is composed by a spiral corrugation pipe or a rectangular corrugation model and a plane pipe. The FEM computed results show that an optimized spiral corrugation pipe model is a inclined angle of $4.7^{\circ}$ and a corrugation height of 1.5mm. And also, a rectangular corrugation pipe model of $90^{\circ}$ is recommended in strength safety rather than a spiral corrugation pipe with an inclined angle. Thus, a corrugated pipe for an increased strength safety is to recommend a reduced pitch and curvature radius of an inclined corrugation.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1293-1298
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• 2006

A numerical analysis was performed to verify how much additional force is induced by short or long pitch rail corrugations in track. The rail corrugations assumed as sine wave having various pitches and depths. The variation of wheel force, displacement and acceleration of rail and sleeper was investigated. In the results, it was shown that each item of the investigation was increased as the pitches and depths become large. It is expected that the results of the parametric study can be used as a preliminary data for the determination of economical maintenance criteria for rail corrugation in the future

• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.32-39
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• 2023

One of the main problems faced in developing India's first HTS power cable was that of shrinkage in length of the double-walled vacuum-insulated cryostat. The shrinkage was due to the evacuation of the annular vacuum space which results in a shorter working cable length. This work reports experimentally observed contraction during evacuation and analyses corrugated pipes/bellows which house the cable core of HTS cables. The effect of corrugation geometry including length, corrugation pitch and depth, diameters of corrugated pipes and thicknesses of pipes is studied numerically to realize the degree of shrinkage due to vacuum as well as chill down. Finally, necessary length compensation and associated cost is determined to tackle the shrinkage issue.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.1
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• pp.1-8
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• 2012

Numerical analysis has been carried out to investigate the fully developed flow and heat transfer characteristics of a plate heat exchanger. Multi-cell models with an inlet part and outlet part are used to perform the numerical simulation. The plate heat exchanger is characterized by a chevron angle of $20^{\circ}$ and a P/H ratio of 2.0~4.0. The working fluid is water and the Reynolds numbers range from 300 to 1,500. The correlation is given in the form of $f=CRe^m$ for the friction factor and $j=CRe^m$ for the Colburn factor. It is found that the fully developed flow starts from the third cell and the Nusselt number increases with decreasing P/H ratios.

• Journal of computational fluids engineering
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• v.9 no.2
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• pp.18-22
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• 2004

Numerical investigation has been conducted to figure out flow behavior and pressure drop characteristics of spirally corrugated steel pipe which is widely used in civil, industrial and agricultural field owing to many advantages such as good corrosion resistance and durability, strength, easy and quick installation. Also the poly-ethylene coating spirally corrugated steel pipe has the long life under condition of sea water immerged. In the present study, flow behavior in the spirally corrugated pipe and influence of P/d/sub h/(ratio of wave pitch to hydraulic diameter) to pressure drop are investigated by CFD with various Reynolds number. And also friction factor is estimated by pressure drop obtained by flow analysis. According to computation results, the flow runs spirally up and down along the spiral corrugation in the vicinity of wall, but the effect of spiral corrugation disappears in core region of pipe. As P/d/sub h/ becomes small, more pressure drop occurs in spirally corrugated Pipe. Besides, friction factor augmentation becomes much larger as Re increases. In case of p/d/sub h/=0.38, Pressure drop and friction factor of spirally corrugated pipe are about four times larger than smooth pipe at Re: 1.46×10/sup 6/.

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.58-64
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• 1999

This paper has been analyzed for the stress behavior problems of the ring knot membrane unit using the finite element method about the pitch design of the membrane unit, which is one of the most important parameters in manufacturing of the membrane type LNG storage tanks. The FEM results have been compared those of the existing pitch design length. The safety problem of the ring knot membrane model, which is considered in this study, does not come out any more no matter what the pitch length is used in the extra large LNG storage tanks. But in the case of the membrane for LNG tankers, it is advantageous to design the pitch short because of fatigue strength caused by repeated loadings. Looking at the deformation behaviors of the membrane corrugation, the deformation of the hight in the y direction occurs $15{\~}50\%$ more than that of the width in the z direction. It shows also that the deformation of the membrane with $-162^{\circ}C$ cryogenic temperature is not so great compared with the deformation by hydrostatic pressure.