• Journal of Biosystems Engineering
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• v.14 no.1
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• pp.24-32
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• 1989

고밀도(高密度)의 열(熱)에너지를 저장(貯藏)하기 위(爲)한 잠열축열장치를 설계(設計), 제작(製作), 작동(作動)하는 경우 잠열축열장치의 사용목적(使用目的)에 적합(適合)한 최적설계(最適設計)와 그 효율적(效率的)인 이용(利用)을 위(爲)해서는 그 부열특성(傅熱特性)이 규명(糾明)되어야 한다. 본(本) 연구(硏究)에서는 실용화(實用化)에 필요(必要)한 이중관형(二重管形) 잠열축열장치의 방열과정(放熱過程)에서의 부열특성(傅熱特性)을 이차원적(二次元的)으로 실험(實驗) 분석(分析)하였으며, 시간변화(時間變化)에 따른 잠열재의 온도변화(溫度變化)와 응고율(凝固率)이 실험분석치(實驗分析値)와 이론분석치(理論分析値)에 있어서 잘 일치하였다. 한편 응고율(凝固率), 방열율(放熱率), 물의 온도변화(溫度變化)에 대(對)한 분석(分析)을 하였다.

• Solar Energy
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• v.10 no.1
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• pp.38-46
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• 1990

For the optimal design and the efficient operation of the double pipe type latent heat storage equipment, the effect of the parameters of the system were analysed. The statistical analysis showed that the theoretical and the experimental results of the volume change rate and the temperature variations were well agreed. Therefore, this theoretical model is reasonable to analyze two dimensional moving boundary problems. In the analysis of the effects of the parameters, the heat extraction fraction and the water outlet temperature of the system as function of the time were analysed depending on the initial temperature of PCM, water inlet temperature, water mass flow rate and the dimension of the inner tube.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.326-332
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• 2000

It should be essentially considered as important points that design of case in electronic product which simultaneously satisfied with structural stability and molding form in respect to developmental period and economical aspect. Especially, a shape of air vents grille, which is made to emit heat happen to be in the internal of product, must satisfy durability and strength but We have no quantitative data because to be done by experience of designer. So, in this study, We will propose that structure of optimal and method of design in air vents grille, which to reduce a lot of loss of time and cost due to trial and error of design and to stabilize in the BALLISTIC Impact test as to estimate strength with external appearance of product, using linear analysis.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.43-48
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• 2003

In this study the optimization of plate-fin type heat sink for the thermal stability is performed numerically. The optimum design variables are obtained when the temperature rise and the pressure drop are minimized simultaneously. The flow and thermal fields are predicted using the finite volume method and the optimization is carried out by using the sequential quadratic programming (SQP) method which is widely used in the constrained nonlinear optimization problem. The results show that when the temperature rise is less than 34.6 K, the optimal design variables are as follows; $B_{1}$ = 2.468 mm, $B_{2}$ = 1.365 mm, and t = 10.962 mm. The Pareto optimal solutions are also presented for the pressure drop and the temperature rise.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.157-160
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• 2008

색온도 및 광색 가변형 100W RGBY LED 투광기를 개발하기 위하여, 투광기의 광학 및 방열기구를 설계하였다. 또한 100W LED 광원모듈을 구동하기 위한 구동회로와 색온도 및 광색 가변을 위한 제어회로를 개발하였다. 이와 같은 설계결과를 적용하여 100W RGBY 투광기의 시제품을 제작하였고, 시제품의 광학적 성능은 협각 $20^{\circ}$, 중각 $50^{\circ}$, 광각 $75^{\circ}$이상을 만족시켰다. 또한 색온도의 변화는 CIE 1931 색좌표에서 흑체궤적과 일치하여 $2,000K{\sim}10,000K$까지 변화하도록 R,G,B,Y LED의 Duty Ratio를 설정하였다. 또한 방열 특성은 100W 구동시 녹색 LED의 온도는 $37{\sim}41.3^{\circ}C$, heatsink의 온도는 $34{\sim}35^{\circ}C$에서 동작되도록 하였다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1156-1166
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• 2004

The shape of plate-fin type heat sink is numerically optimized to acquire the minimum pressure drop under the required temperature rise. In constrained nonlinear optimization problems of thermal/fluid systems, three fundamental difficulties such as high computational cost for function evaluations (i.e., pressure drop and thermal resistance), the absence of design sensitivity information, and the occurrence of numerical noise are commonly confronted. Thus, a sequential approximate optimization (SAO) algorithm has been introduced because it is very hard to obtain the optimal solutions of fluid/thermal systems by means of gradient-based optimization techniques. In this study, the progressive quadratic response surface method (PQRSM) based on the trust region algorithm, which is one of sequential approximate optimization algorithms, is used for optimization and the heat sink is optimized by combining it with the computational fluid dynamics (CFD).

• Composites Research
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• v.35 no.3
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• pp.175-181
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• 2022

Due to the increasing number of wireless communication devices in mmWave frequency bands, there is a high demand for electromagnetic interference (EMI) shielding and heat dissipating materials to avoid device malfunctions. This paper proposes an EMI shielding composite film with a high heat dissipation characteristic. To achieve this, a conductive grid is integrated with a polymer-based composite layer including magnetic and heat dissipating filler materials. A high shielding effectiveness (>40 dB), low reflection shielding effectiveness (<3 dB), high thermal conductivity (>10 W/m·K), thin thickness (<500 ㎛) are simultaneously achieved with a tailored design of composite layer compositions and grid geometries in 5G communication band of 26.5 GHz.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.983-984
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• 2012

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.112-112
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• 2007

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.313-318
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• 2020

Since the engineering plastics having a melting point of higher than 300 degrees have a high mechanical rigidity, chemical resistance, friction and abrasion performance, those are being highlighted as metal replacement materials in various industries. In this study, 3D printer nozzle with excellent heat dissipation characteristics are designed and analytically verified to form engineering plastics with high melting points in 3D printers based on the melt-lamination modeling method. In order to insulate between the heat block heated to a melting point of filament material and the upper part of the nozzle where the filament is transferred, the heat brake part with low thermal conductivity was designed to have two separate parts, and a cooling fin structure is further applied to the heat brake part to lower steady-state temperature by air convection. Optimized structural design on FDM nozzle part reduces the temperature at the heat sink and at the end part of heat brake by 50% and 14% respectively, compared to the conventional BCnozzle structure.