• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.69-78
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• 1999

We present the results of one-dimensional numerical simulations of SNR evolution in the in­homogeneous medium considering the effects of the evaporation of the cloud and the thermal conduction. We have included the effects of changing evaporation rate as a function of cloud size and the ambient temperature so that the clouds could be evaporated completely before they reach the center of the SNR. The heat conduction markedly changes the density distribution in the remnant interior. To explain the observed morphologies of the centrally peaked X-ray SNRs(for example W44), the maximal thermal conduction is required. However, this is unlikely due to the magnetic field and the turbulent motion. The effects of the evaporation of the cloud and the thermal conduction described here may explain the class of remnants observed to have centrally peaked X-ray emmision.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.6
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• pp.60-67
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• 2002

A precise measurement of field test was performed to estimate the thermal performance of the forced convection electric air heater by experiment. Air temperature, flow rate and electrical power input were measured with the related measurement sensors, and acquisition methods for the measured data were studied to estimate the thermal performance of the tested air heater effectively. To determine the mean air temperature at the flow cross-section, measuring positions were chosen by considering the flow velocity profile and the equally divided cross-sectional area. From the experimental results, thermal efficiency was obtained accurately as an indication of the tested heating system performance.

• Transactions on Electrical and Electronic Materials
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• v.13 no.3
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• pp.153-156
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• 2012

In order to develop electrical insulation materials, epoxy/micro-silica composite (EMC) and epoxy/micro-silica/nano-silicate composite (EMNC) were prepared, and their tensile and flexural strength, AC insulation breakdown strength and thermal conductivity and thermal expansion coefficient were compared. Nano-silicate was prepared in an epoxy matrix by our AC electric field process. All properties of the neat epoxy were improved by the addition of micro-silica, which was improved much further by the addition of nano-silicate to the EMC system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.42-47
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• 2014

The use of BLDC motor in Vehicle and industrial field, it is operated by continuous and intermittent driving. When the intermittent driving is occurred by the rise and fall of temperature repeatedly, it was represented by different characteristics in case of continuous driving. So, it is very important that heat source estimation according to the duty ratio. In this paper, temperature characteristics according to the operating method of BLDCM was calculated by using the thermal equivalent circuit, and the validity of the study was demonstrated as compared to the calculated and experimental results.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.990-992
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• 2005

This paper presents a new magneto-thermal finite element analysis for predicting the temperature rise of the EHV GIS bus bar. The power losses of a bus bar calculated by the magnetic field analysis are used as the input data to predict the temperature rise for the thermal analysis. The heat-transfer coefficients on the boundaries are analytically calculated by applying the Nusselt number considering material constant and model geometry for the natural convection. The temperature distribution in a bus bar by coupled magneto-thermal finite element analysis shows good agreement with the experimental data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.895-901
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• 2012

In order to application for high voltage heavy electric equipments, epoxy/microsilica 60 wt%/nano layered silicate composites (EMNC_60) and epoxy/microsilica 65 wt%/nano layered silicate composites (EMNC_65) respectively was synthesized by our electric field dispersion method and the result was obtained completely dispersion state. Thermal properties such as glass transition temperature (Tg) and thermal expansion coefficient, and DMA characteristics were studied, and mechanical properties such as tensile and flexural tests were performed. AC electrical insulation strength was also tested. The study on thermal property, EMNC_65 was better than EMNC_60 and mechanical, electrical properties much improved EMNC_60 compared with EMNC_65.

• Journal of Power System Engineering
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• v.10 no.4
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• pp.133-138
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• 2006

Effective thermal conductivity of particulate reinforced composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory. The predicted results are compared with the experimental results from the literature. The model composite is polymer matrix filled with ceramic particles such as silica, alumina, and aluminum nitride. The preliminary examination by Eshelby type model shows that the predicted results are in good agreements with the experimental results for the composite with perfect spherical filler. As the shape of filler deviates from the perfect sphere, the predicted error increases. By using the aspect ratio of the filler deduced from the fixed filler volume fraction of 30%, the predicted results coincide well with the experimental results for filler volume fraction of 40% or less. Beyond this fraction, the predicted error increases rapidly. It can be finally concluded from the study that Eshelby type model can be applied to predict the thermal conductivity of the particulate composite with filler volume fraction less than 40%.

• Advances in materials Research
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• v.6 no.4
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• pp.349-361
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• 2017

The nonlinear thermal buckling load parameter of the laminated composite panel structure is investigated numerically using the higher-order theory including the stretching effect through the thickness and presented in this research article. The large geometrical distortion of the curved panel structure due to the elevated thermal loading is modeled via Green-Lagrange strain field including all of the higher-order terms to achieve the required generality. The desired solutions are obtained numerically using the finite element steps in conjunction with the direct iterative method. The concurrence of the present nonlinear panel model has been established via adequate comparison study with available published data. Finally, the effect of different influential parameters which affect the nonlinear buckling strength of laminated composite structure are examined through numerous numerical examples and discussed in details.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.5
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• pp.364-371
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• 2007

The former studies for expanding a balcony space were tend to be focused on only quantitative aspects. In this study, the characteristics of balcony space on thermal on vironment in apartment house were analysed. First, the effect of the balcony space on thermal environment of living space was analysed by field measurement. Second, the temperature distribution of the bedroom and heating/cooling load with the balcony expansion were analysed by numerical simulation.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.847-853
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• 2006

The former studies for expanding a balcony space were tend to be focused on only quantitative aspects. In this study, the characteristics of balcony space on thermal environment in apartment house were analysed. First, the effect of the balcony space on thermal environment of living space was analysed by field measurement. Second, the temperature distribution of the bedroom and heating/cooling load with the balcony expansion were analysed by numeric at simulation.