As the demand for appropriate heat dissipation measures to improve product stability and performance continues to increase and product design becomes highly integrated, research to improve heat transfer performance while maintaining the same area or size is required. In this study, the sample-shaped aluminum plate was treated as upper-coating, and the thickness of the coating was divided into 1mm, 2mm, and 3mm, respectively, and the coating material was applied with silver, copper, and graphene. The temperature condition of the heat source was set to 473K, and heat dissipation analysis was performed under natural convection. The thermal performance was compared and analyzed through temperature distribution, flow velocity distribution, and heat flux, and it was confirmed that the high thermal conductivity of graphene compared to other materials had a dominant effect on the increase in the conduction heat transfer rate. And it was confirmed that the high surface temperature of the graphene coating also increased the heat transfer rate by convection, thereby enhancing the heat dissipation effect.

LED (Light Emitting Diode) 조명은 차세대 조명으로 주목 받고 있으나 조명에서 방출되는 열에 의해 조명의 수명이 상당히 단축되는 문제가 있다. 이를 해결하기 위해 Al, Al-Zn 합금, Mg 합금 등의 열 전도성과 가벼운 재료를 heatsink로 사용되고 있다. 하지만 출력이 높고, 사용되는 조명의 수가 많을수록 heatsink의 크기가 커져야 하는 문제가 있다. 이를 해결하기 위해 본 연구에서는 heatsink 표면의 방열 성능을 향상시키기 위해 spray coating 방식에 비해 도막 형성이 균일한 전착도장 (electrodeposiion coating) 방식의 도료를 합성하였다. 열전도도를 향상시키기 위해 전도성 구형 안료와 침상 안료를 사용하였고, 이를 비교하기 위해 heatsink의 온도 변화를 측정하였다. 그리고 도막의 표면을 Scanning Electron Microscope를 통해 관찰 하였다. 안료의 첨가에 따라 코팅막에 복잡한 구조가 만들어졌고 열을 전도할 수 있는 경로를 제공하여 방열 성능이 향상됨을 확인하였다.

In this study, we analyzed the radiant heat performance of ballast fin when the aspect ratio of the fin of ballast was changed. The minimum size of the mesh was 0.02 mm, and the grid number was about more than 11 thousand. In order to analyze the radiant heat performance of ballast fin, the aspect ratio of fin was 1.00(2 mm:2 mm), 1.80(1.5 mm:2.7 mm), and 0.56(2.7 mm:1.5 mm) respectively; that the heat transfer area was constantly 0.4 mm 2 . The numerical condition was that heat flux was constantly 1×10 5 W/m 2 , and measuring times were 0.1 second, 0.2 second, 0.5 second, 2 seconds, 5 seconds and 10 seconds respectively. The temperature values of fin at the 1.00 and 1.80 of aspect ratios were extremely large when heat flux time was 10 seconds. As a result, the maximum value of radiant heat performance of ballast fin appeared to the aspect ratio of 1.80.

This research is to investigate the cooling performance analysis of the heat sinks for LED light with four different fin types and two different fin numbers (16EA and 64EA) of heat sinks. Temperature distributions of fins over the flow domain are numerically calculated for the optimum design of heat sink fin types with uniform initial temperature of the bottom of the fins. According to the calculations of convective heat transfer coefficient between fin and atmosphere in the flow domain, S-curve fin type of heat sinks with 64EA of fins reveals the highest cooling performance of the heat sink fin types in the present cooling heat sink model.