• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.461-469
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• 2017

A segment of the wave board has been expressed as a submerged line segment in the two dimensional wave flume. The lower end of the line segment could be extended to the bottom of the wave flume and the other opposite upper end of the board could be extended to the free surface. It is assumed that the motion of the wave board could be defined by the sinusoidal motion in horizontal direction on either end of the wave board. When the amplitude of sinusoidal motion of the wave board on lower and upper end are equal, the wave board motion could express the horizontally oscillating submerged segment of piston type wave generator. The submerged segment of flap type wave generator also could be expressed by taking the motion amplitude differently for the either end of the board. The pivot point of the segment motion could play a role of hinge point of the flap type wave generator. Simplified analytic solution of oscillating submerged wave board segment in water of finite depth has been derived through the first order perturbation method at two dimensional domain. The case study of the analytic solution has been carried out and it is found out that the solution could be utilized for the design of wave generator with arbitrary shape by linear superposition.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.28-41
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• 2019

We carried out performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor. We analyzed transient-dynamic behavior of fluids inside the steam generator to vent into a sodium dump tank or a water dump tank when tubes in the steam generator were broken to cause a large-water-leak accident. Accordingly, we preliminarily evaluated design requirements of our system. Our results showed that sodium in the shell side of the steam generator and in Intermediate Heat Transport System was completely vented within 50 s and feed water in the tube side of the steam generator was completely vented within 2.5 s. It was analyzed that pressure of the tube side of the steam generator was higher than pressure of the shell side of the steam generator, which showed that sodium in the shell side did not flow into the tube side. Our results are expected to be used as basis information to performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.5
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• pp.283-288
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• 2016

A non-lethal weapon is a device that can subdue targets without causing death or mortal wounds. A high-intensity flash generator can negate electro-optical sensors and cause temporal flash blindness with a high intensity of light. In this study, we derive the design parameters of an explosive-driven high-intensity flash generator that uses the interaction of plasma caused by the detonation of explosives with surrounding inert gas. To determine the design parameters of the flash generator, we analyze test results measured using optical sensors. The experimental results show that the light intensity of xenon gas is about four times higher than that of air. In addition, the intensity increases with the weight of the explosive, and the inert gas cross-sectional area encountered a shock wave in the airframe. The light intensity caused by a double-initiation generator is about two times higher than that of the single-initiation generator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5A
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• pp.441-450
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• 2006

Recently, with the exponential growth of the number of Internet users, IP traffic which occupies more than 90 percent of the entire Internet traffic affects significantly to the performance of networks. Therefore, the design of the self-similar traffic generator reflected the feature of IP traffic is very important to design the networks efficiently and evaluate the performance of it correctly. In this paper, we design the self-similar traffic generator using OPNET. In order to implement the self-similar characteristics, ON-OFF sources with Pateto distribution are employed and aggregated. The designed self-similarity traffic generator is evaluated and verified with R/S plot, variance time(VT) plot under the various offered loads and the number of sources. It is expected that the designed self-similar traffic generator can be put to practical use when wire or wireless networks is designed and verified as well as it can be useful to decide the specific parameter value for Internet traffic modeling.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.152-156
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• 2010

This study is focused on the channel design of bipolar plate in the electrode of hydrogen gas generator. The characteristics of hydrogen gas generation was studied in view of efficiency of hydrogen gas generation rate and a tendency of gas flow through the riv design of electrode. Since the flow rate of generated gas is the most crucial in determining the efficiency of hydrogen gas generator, we adopted the commercial analytical program of COMSOL $Multiphysics^{TM}$ to calculate the theoretical flow rate of hydrogen gas from the outlet of gas generator.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.224-231
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• 2003

The purpose of this study is to review and validate the seismic analysis procedures of turbine-generator foundation specified in the Korea Building Code which adopts equivalent static analysis. Typical machines and foundations were chosen and various kinds of parametric studies were peformed and the results were compared with the detail dynamic analysis. The general trend of the study results showed that the most of the computed responses of equivalent static analysis are smaller than those of the dynamic analyses(response spectrum analysis and time history analysis), which implies the existing seismic analysis technique using the existing Building Code may give unconservative design results. The results also showed that the seismic loads are one of the governing design parameters of the turbine-generator foundations.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.909-914
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• 2001

After burner which is main part of inert gas generator(IGG) is studied for the development of IGG. The results of many experimental equations are applied to estimate characteristics of the spray nozzle and evaporation of spray, and selected the optimum design point of after burner. The selected design point of after burner are validated experimentally through the pilot plant of after burner. The flame stability is favorable at design point(150mm), that distance from stabilizer to nozzle. The emission of $NO_x$ and CO is lower than gas turbine combustor which was used in primary combustor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.75-80
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• 2014

The small wind turbines has the merits of setting up with low costs by individuals, and get the energy saving effects that, it has the secured, separate markets from the big range systems, and the developing of it is continuously proceeding. The objective of this paper is to provide the design characteristics analysis of a permanent magnet synchronous generator(PMSG) skewed for magnet of rotor, the main advantage to be explored with the use of a split core design is the reduction in manufacturing costs and its simplicity in manufacture, compared to the manufacturing costs of a core skew PM machine. This thesis is aiming mainly analyzing the characteristics of the prototype to verify through Finite Element Method(FEM) and tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.39-51
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• 2014

This paper deals with design of a direct-coupled, small-scaled permanent magnet generator (PMG) for wind power application. First, this paper determines rated power and speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit including slot opening, teeth width and yoke thickness is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot considering winding packing factor. Finally, finite element (FE) method is employed in analyzing the details of the designed PMG and, test results such as back-emf measurements are given to confirm the design.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.1
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• pp.39-44
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• 2019

A high-temperature superconducting(HTS) generators have been actively studied because of its advantages of weight, size, and efficiency. A large-scale superconducting wind power generator becomes a very low-speed high-torque rotating machine. In these machines, high electromagnetic force and torque are important issued. Two generators connected in series on one shaft design are one of the solution to overcome the high torque problem. In this paper, the authors design and analyze a 15 MW class HTS generator. The 15 MW HTS generator is confirmed in terms of magnetic field distribution and torque performance using a 3D finite element method. As a result, the designed generators generates less torque than a conventional generator. The designed 15 MW superconducting generator will be effectively utilized in the construction of the large-scale wind power generation system.