초록 ▼

1. 자연대류 사각핀 알루미늄 히트싱크에 미치는 핀 슬릿의 영향 연구
- 슬릿핀의 무차원 핀 길이가 42.85일 때 최대 6.7% 열전달 향상
- 슬릿판에 대한 새로운 자연대류 열전달 상관식 제시
2. 삼각형 박막절곡 핀 방열기의 방열 성능 해석 및 압출성형 방식의 plate fin 방열기와 성능비교
- 기존의 plate fin 방열기에 비해 열 저항이 약 18% 감소
- 박막절곡 핀 방열기의 슬릿수가 증가할수록 열 저항 감소
3. Jet Impinging 채널 내에서 pin f

1. 자연대류 사각핀 알루미늄 히트싱크에 미치는 핀 슬릿의 영향 연구
- 슬릿핀의 무차원 핀 길이가 42.85일 때 최대 6.7% 열전달 향상
- 슬릿판에 대한 새로운 자연대류 열전달 상관식 제시
2. 삼각형 박막절곡 핀 방열기의 방열 성능 해석 및 압출성형 방식의 plate fin 방열기와 성능비교
- 기존의 plate fin 방열기에 비해 열 저항이 약 18% 감소
- 박막절곡 핀 방열기의 슬릿수가 증가할수록 열 저항 감소
3. Jet Impinging 채널 내에서 pin fin 방열기의 성능 최적화를 위한 수치해석연구
- 동일한 유량조건에서 최적화되지 않은 fin에 비해 약 1.1~2.7 배 성능향상
- 최적 다공도를 예측할 수 있는 상관식 제시
4. Plate fin, in-lin round pin-fin, staggered round pin-fin, offset strip-fin 방열기 열저항 해석 알고리듬 개발
- 팬-방열기의 성능해석 알고리듬 개발
- 방열기의 방열 성능비교
5. 정보통신기기 냉각요 최적 설계 및 해석 소프트웨어 엔진 개발 완료

Abstract ▼

In modern telecommunication devices, maintaining chip junction temperature below a tolerable limit by using well designed heat sinks is crucial. For this reason, various types of heat sinks with extended surfaces have been developed. Extruded Plate-fin heat sinks are frequently found in natural conv

In modern telecommunication devices, maintaining chip junction temperature below a tolerable limit by using well designed heat sinks is crucial. For this reason, various types of heat sinks with extended surfaces have been developed. Extruded Plate-fin heat sinks are frequently found in natural convection and low heat-flux forced convection devices. For applications with high fluxes, pin-fin, offset strip fin and louvered fin heat sinks are preferable. Although such densely packed and thin finned heat sinks can dramatically increase the heat transfer surface area, they are associated with the penalty of much higher pressure drop through heat sinks. Severe pressure loss in a fan-added heat sink results in a substantial reduction of airflow rate, and consequently, it yields undesirable increase of convective thermal resistance, irrespective of the augmented surfaces of the heat sinks. Therefore, the optimization of heat Sink geometry and the precise performance analysis are indispensible to the advance of IT hardwares
In the present project, therefore, we aim to develop design and ana1ysis software for various heat sinks under natural convection as well as forced convection. The contents obtained in the present project are the followings:
First, experiments have been performed to investigate on natural convective heat transfer from a slit-fin heat sink. Results are obtained over a wide range of Rayleigh number of 2.15${\times}$10$^{10}$${\leq}$8.12${\times}$10$^{10}$. The slit fin enhances 6.7% thermal performance of the natural convection heat sink. A correlation for predicting the thermal performance is proposed.
Second, experiments have been carried out to investigate the convective heat transfer characteristics from triangular folded fin heat sinks in a suction-type fan duct. Thermal performance of triangular folded fin heat sinks is evaluated in terms of thermal resistance of heat sinks according to f1ow velocity and fan power. The results obtained show that the present triangular folded-fin heat sink shows a higher thermal performance compared to a conventional extruded plate-fin heat sink. Especially, a perforated slit folded-fin heat sink displays a lower thermal resistance. As the number of slit fabricated on the perforated folded fins increases, thermal performance is more pronounced.
Third, a numerical study has been carried out to optimize thermal performance of a pin-fin heat sink. A pin-fin heat sink placed horizontally in a channel is modeled . as a hydraulically and thermally anisotropic porous medium. A uniform heat flux is prescribed at the bottom of the heat sink. Comprehensive n1lmerical solutions are derived from the governing Navier-Stokes and energy equations using the Brinkman-Forchheimer extended Darcy model and the local thermal non-equilibrium (LTNE) porous model for the region occupied by the heat sink Optimum porosity for maximum heat dissipation depends on the pin-fin thickness, the pin-fin height and the Reynolds number. A correlation for predicting the optimum porosity for a Pin-fin heat sink is proposed. Generally, in the case of thin pin-fin the heat sink should be designed to have high porosity while in the case of thick fin the heat sink should be designed to have relatively lower porosity.
Forth, thermal performance of plate fin, round pin-fin and offset strip-fin heat sinks with a duct- flow type fan arrangement was analytically evaluated. A constant temperature, 6 mm thick heat sink base plate is assumed so that thermal spreading resistance is not involved. The operating point on the fan curve is based on the flow pressure drop impedance curve through a heat sink using the friction factor correlation for the chosen heat sink. Results obtained show that optimized round pin-fin heat sinks provide 32.8%- to-46. 4% higher convective thermal resistance compared to an optimized plate-fin heat sink. The optimized offset strip-fin heat sink shows a slightly lower convective thermal resistance than the Plate-fin heat sink. As the offset strip length decreases, however, thermal performance seriously deteriorates.
Fifth, using the modified correlation for natural convection heat sinks and the solution algorithm for fan-added forced convection heat sinks, a GUI-based program for design and analysis of heat sinks has been developed.

목차 Contents

• 제1장 서론...15
• 제2장 국내외 기술개바 현황...17
• 제3장 연구개발수행 내용 및 결과...19
• 제1절 자연대류용 방열기 기술자료 조사 및 소프트웨어 엔진 개발에의 적용...19
• 제2절 자연대류 방열기의 방열 성능에 미치는 핀 슬릿의 영향...27
• 제3절 채널유동에서 삼각형 박막절곡 히트 싱크의 방열 성능 해석...41
• 제4절 Jet Impinging 채널에서 이방성 LTNE 다공정 모델을 적용한 Pin-fin 히트싱크 최적화 연구...47
• 제5절 CPU 냉각을 위한 팬 히트 싱크의 방열 성능 해석...61
• 제6절 정보통신기기용 방열기 최적 설계 및 해석 소프트웨어 개발...75
• 제4장 목표달성도 및 관련분야에의 기여도...81
• 제5장 연구개발결과의 활용계획...83
• 제6장 연구개발과정에서 수집한 해외과학기술정보...85
• 제7장 참고문헌...89