• Journal of Radiation Industry
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• v.17 no.4
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• pp.443-449
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• 2023

KAERI(Korea Atomic Energy Research Institute) is conducting research and development of large-scale radiation generators and the latest radiation measuring instruments. In particular, research and development of security screening equipment using an electron beam accelerator and a neutron generator is in progress recently. Globally, 20 ft containers are used to transport imports and exports, and electron beam accelerators are radiation sources to measure the shape of the material inside the container during customs inspections in each country. KAERI is developing a device that can use an electron beam accelerator and a neutron generator sequentially to grasp the shape of various materials as well as the location of the internal target material. In this study, when using the neutron generator, the radiation dose and the degree of activation by neutron for the facility and surrounding environment, facility equipment were simulated using MCNP and FISPACT code. As a result, the shielding structures inside and outside the radiation control area were satisfactory to the reference level established conservatively based on the Korean Nuclear Act.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.499-505
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• 2001

The objective of the paper was to measure the pressure drop and to investigate the recirculation region of the conical orifices used in Kwang-yang Iron & Steel Company. The flow field with water used as a working fluid was the turbulent flow for Reynolds number of $2{\times}10^4$. The effective parameters for the pressure drop and the recirculation region were the conical orifice's inclined angle (${\theta}$) against the wall, the interval(L) between orifices, the relative angle of rotation(${\alpha}$) of the orifices, the shape of the orifice's hole(circle, rectangle, triangle) having the same area. It was found that the shape of the orifice's hole affected the pressure drop and the flow field a lot, But the other parameters did not make much differences to the pressure drop. The PISO algorithm with FLUENT code was employed.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.4
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• pp.30-36
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• 2003

Lately, the cavitation and erosion phenomena in the rudder have been increased for high-speed container ships. However, cavitation is not prone to occur in model experiments because of low Reynolds number. In order to predict the cavitation phenomena, the - analysis of the viscous flow in the rudder gap is positively necessary In this study, numerical calculation was applied to the two-dimensional flow around the rudder gap using FLUENT code. The velocity and pressure field were numerically acquired and cavitation phenomena could be predicted. And the case that the round bar was installed in the rudder gap was analyzed. For reducing the acceleration force when fluid flow through the gap, modified rudder shape is proposed, It is shown that modified rudder shape restrain the pressure drop at the entrance of the gap highly both in the computational results and in the model experiment, and reduce the cavitation bubbles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.773-777
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• 1995

This thesis attempt to explore the shape of stress wave propagation of 3-dimensional stress field which is made in the process of time increment. A finite element code about 3-dimensional stress wave propagation is developed for investigating the changing shape of the fracture by the impact load. The Finite Element Code, which is the solution for the 3-dimensional stress wave analysis, based on Galerkins and Newmark- .betha. method at time increment step. The tensile stress and compressive stress become larger with the order of the middle, the upper and the opposite layers when the impact load is applied. In a while the shear stress become larger according to the order of the upper, the middle and the opposite layers when impact load applied.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.106-114
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• 1994

A new merging technique is adopted for combining rectangular parallelepipes produced by 2-D rectangular code into more intuitive 30D volume elements. Rectangular parallelepiped codes (RP codes) can be used in volume-based representation of a three-dimensional object. We proposed more regularity-conserving 2-D rectangular coding scheme to merge rectangular cells represented by RP codes in three-dimensional space. After being constructed from modified 2-D rectangular code, 3-D RP codes are merged in the two orthogonal directions using new merging algorithm. The shape of merged 3-D object reconstructed by proposed algorithm is shown to be much closer to the original object shape than that of conventional RP codes. The storage requirement of merged object can be also reduced.

• 한국전산유체공학회:학술대회논문집
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• 1996.05a
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• pp.111-117
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• 1996

The Delaunay triangulation technique was tested for complicated shapes of computational domain. While a simple geometry, both in topology and in geometry, was discretized well into triangular elements. a complex geometry often failed in triangularization. A complex geometry should be devided into smaller sub-domains whose shape is simple both topologically and geometrically. The present study developed the data structures not only for relationships among neibering elements but also for shape information, and coupled these into the Delaunay triangulation technique. This approach was able to enhance greatly the reliability of triangularization specially in complicated shapes of computational domains. The GUI (Graphic User Interface) and OOP (Object-Oriented Programming) were used in order to develop the user-friendly and efficient computer code.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.7 s.238
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• pp.1013-1021
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• 2005

In this paper, we developed an automatic design optimization system for parametric shape optimization of cooling passages inside axial turbine blades. A parallel three-dimensional thermoelasticity finite element analysis code from an open source system was used to perform automatic thermal and stress analysis of different blade configuration. The developed code was connected to an evolutionary optimizer and built in a design optimization system. Using the optimization system, 279 feasible and optimal solutions were searched. It is provided not only one best solution of the searched solutions, but also information of variation structure and correlation of the 279 solutions in function, variable, and real design spaces. To explore design information, it is proposed a new interpretation approach based on evolutionary clustering and principal component analysis. The interpretation approach might be applicable to the increasing demands in the general area of design optimization.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.501-506
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• 2000

Many research in Robot control has effectively proceeded on the development of Aritficial Intelligence Robot which is able to apply to the uncertain and monotonous operations which are repeated continuously in the industrial field. In this study, the precise shape recognition of base metal for welding was gained by mono CCD camera, and the gained data was transformed into Decimal code through Image Board in computer. And the Fuzzy Logic control system designed by use of Fuzzy rule was built to judge whether the base metals were precisely matched or not with Decimal code. Machanically manipulated Robot syst em was linked to Fuzzy Control system through image information, and ultimately, these systems will be able to apply for production system.

• Journal of computational fluids engineering
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• v.14 no.1
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• pp.45-52
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• 2009

Ice accretion may occur when the sold surface passes through the clouds containing supercooled water droplets. In the case of aircraft, it can result in serious performance degradation and safety hazard. In this study, numerical analysis code has been developed to predict the rime ice shapes on a 2-D airfoil and the computation results are validated against experimental data of NASA and other computation results of well-known ice prediction code, LEWICE. In addition, the effects of various numerical parameters on the ice shape have been systematically investigated.

• Journal of KSNVE
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• v.9 no.2
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• pp.310-316
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• 1999

4-Pole parameter method based on an acoustic theory is very popular for the analysis of the acoustic behavior of the car exhaust system. However, this method is applicable only for the simple shape of acoustic elements of the muffler. Numerical methods such as FEM(Finite Element Method) or BEM(Boundary Element Method) can also provide acceptable results for the acoustic analysis of the car exhaust system. Even though these numerical methods have benefits for the analysis of complicated shape of acoustic elements of the muffler, time consuming is another problem during modeling and numerical calculation. Combining benefits of both methods, the new code called the hybrid method for car exhaust system is introduced. And the developed code is utilized for calculation of the transmission loss of a main muffler of an automobile comparing with the experimental results.