초록 ▼

첨단 고성능 전열기기에서의 효과적인 열전달 촉진 및 억제 기술 개발을 목표로 다음의 3가지 주제를 중심으로 연구가 진행되었다.
1. 열전달 억제 및 촉진 기술
휜과 열교환기의 열전달 특성 연구, 3차원 6면 요철이 주기적으로 위치한 관 내 열전달 상승에 관한 연구, 자연대류공진을 이용한 밀폐용기 내부 열전달 촉진 기술 개발, 실제적 조건을 가지는 시스템의 유동공진을 이용한 열전달 촉진 기술 개발, MEMS 공정 기술을 이용한 슈퍼 단열 칩의 개발의 열전달 억제 및 촉진 기술 개발이 이루어졌다.
2. 반도체 냉각 기술

첨단 고성능 전열기기에서의 효과적인 열전달 촉진 및 억제 기술 개발을 목표로 다음의 3가지 주제를 중심으로 연구가 진행되었다.
1. 열전달 억제 및 촉진 기술
휜과 열교환기의 열전달 특성 연구, 3차원 6면 요철이 주기적으로 위치한 관 내 열전달 상승에 관한 연구, 자연대류공진을 이용한 밀폐용기 내부 열전달 촉진 기술 개발, 실제적 조건을 가지는 시스템의 유동공진을 이용한 열전달 촉진 기술 개발, MEMS 공정 기술을 이용한 슈퍼 단열 칩의 개발의 열전달 억제 및 촉진 기술 개발이 이루어졌다.
2. 반도체 냉각 기술
경사진 충돌 제트를 이용한 핀 휜 히트 싱크의 열특성 연구, 충동 제트를 가지는 마이크로 채널 히트 싱크에서 유체 및 열 성능에 관한 실험적 연구, MMC (Manifold Microchannel) Heat Sink 수치 최적화, 열원 냉각용 루프 써모 사이폰의 작동 특성 연구, Micro/Miniature Heat Pipe 열성능 최적화 연구의 반도체 냉각 기술에 관한 연구가 이루어 졌다.
3. 최첨단 측정 기술
SRS를 이용한 연소가스의 온도분포 측정기술 개발, 레이저를 이용한 열전달계수 측정기술 개발, Micro-thermal Sensor Array 개발, Diode Temperature Sensor Array(DTSA) 개발의 열전달 관련 측정 기술 개발을 수행하였다.

Abstract ▼

Study on heat transfer enhancement and suppression technology for high-performance thermal devices has been performed. Largely, the present work is divided into three parts: heat transfer enhancement and suppression technology, Electric cooling technology, and Effective measurement technology.
Th

Study on heat transfer enhancement and suppression technology for high-performance thermal devices has been performed. Largely, the present work is divided into three parts: heat transfer enhancement and suppression technology, Electric cooling technology, and Effective measurement technology.
The details of heat transfer enhancement and suppression technology are as follow:
A) Flow and heat transfer in a plate-finned circular-tube assembly is examined using a naphthalene sublimation technique. A placement of single tube is better downstream and the staggered tube alignment is found to give greater heat/mass transfer by the development of the vortex shedding than the in-line case.
B) three dimensional numerical analysis and steepest descent method is used. The optimum set of shape parameters is provided to minimize thermal resistance for a given pump power. It is also shown that width and depth channel is the major parameters.
C) A numerical and analytical study is conducted on the buoyant convection in a side-heated cavity under gravity and oscillations as well as with uniform internal heat generation. The theoretical predictions of the resonance frequencies, based on the modes of internal gravity oscillations, are in accord with the present numerical data. The computed results suggest that resonance takes place when the frequency of oscillations matches the basic mode of internal gravity oscillations.
D) A numerical and analytical study is conducted on the buoyant convection of an incompressible fluid in a rectangular cavity and enhancement of heat transfer in a realisticcc system. Realistic viscous fluids, such as Newtonian fluids with a temperature-dependent viscosity or purely viscous non-Newtonian power-law fluids, are selected as a working fluid.
E) Transmission characteristics are heavily dependent on the vacuum gap size, number of layer, and the thickness of the coated metal. Thermal ttansmission across a layer increases fast to an upper limit as the thickness of the gap and the coated metal decrease below the wavelength of typical thermal radiation. With a small number of layers, insulation performance per each layer is relatively poor, while it approaches an asymptotic limit with greater number of layers.
In addition, the following results are obtained regarding electric cooling technology.
A) From the results using the PIV, the jet impinges over a wide span of the heat sink with a large recirculation in the upper free space and occasionally with another smaller one in the corner. Thermal experimentation's results show that impinging angle of $55\textdegree$ degree show the heat transfer capability.
B) The objective of the present study is to investigate the fluid flow and heat thansfer phenomena for the microchannel heat sink sunbject to an impinging jet experimentally. For this, correlations for the pressure drop and the thermal resistance is obtained in terms of geometric variables and the Reynolds number based on the experimental results. And also optimum sizes of the microchannel heat sink subject to an impinging jet are presented by using the correlations for the pressure drop and the thermal resistance under the fixed pumping power condition.
C) Three dimensional numerical analysis was carried out. The major parameters of interest are arrangement of ribs, rib interval and aspect ratio for a hexahedral rib channel. It is shown that staggered arrangement and large rib aspect ratio increase the heat transfer.
D) To investigate the overall performance of loop thermosyphon, we have perfrrmed various experiments varying three parameter: input power of the heater, working fluid and filling ratio of the working fluid. In addition, flow visualization using a high speed camera is carried out.
E) A mathematical model for heat and mass transfer in a miniature heat pipe with a grooved wick structure is developed and solved analytically to yield the maximum heat transport rate and the overall thermal resistance under steady-state conditions. This model is verified by experimental syudy and numerical optimization is performed to enhance the thermal performance of the miniature heat pipe.
Finally, we have developed effective measurement technology for temperature distribution and heat transfer coefficient as follow:
A) The spectral remote sensing(SRS) inversion technique to determine the complex, line-of sight temperature distribution from the gas emission data at $CO_2$ 4.3MICRON IS INVESTIGATED. The gas database is generated and experimentally validated. Three inversion schemes are proposed and verified through experimental systems.
B) A basic study is performed to measure surface-coated naphthalene thickness using laser. It is shown that there is the linear correlation between the naphthalene thickness and the output voltage of the photo diode. The optical method to measure surface-coated naphthalene thickness is laid the groundwork for by this study.
C) The micro-thermal sensor array is developed to measure temperature distributions at the surface of microstructures. Microfabrication processes for the micro-thmperature distributions at the surface of microstructures. Microfabrication processes for micro-thermal sensor array have advantages, simple and convenient processes.
D) A Diode Temperature Senser Array (DTSA) for spatially and temperally resolved measurements of temperature fluctuations on the surface of the microstructure.

목차 Contents

• 제1장 연구개발과제의 개요...12
• 제2장 국내외 기술개발 현황...14
• 제3장 연구 개발 수행 내용 및 결과...17
• 3.1 열전달 억제 및 촉진 기술...17
• 1.1 휜과 열교환기의 열전달 특성 연구...17
• 1.2 3차원 6면 요철이 주기적으로 위치한 관 내 열전달 상승에 관한 연구...28
• 1.3 자연대류공진을 이용한 밀폐용기 내부 열전달 촉진 기술...33
• 1.4 실제적 조건을 가지는 시스템의 유동공진을 이용한 열전달 촉진 기술...45
• 1.5 MEMS 공정 기술을 이용한 슈퍼 단열칩의 개발...70
• 3.2 반도체 냉각 기술...78
• 2.1 경사진 충돌제트를 이용한 핀 휜 히트 싱크의 열특성 연구...78
• 2.2 충돌 제트를 가지는 마이크로 채널 히트 싱크에서 유체 및 열 성능에 관한 실험적 연구...83
• 2.3 MMC (Manifold Microchannel) 히트 싱크 수치 최적화...99
• 2.4 열원 냉각용 루프 써모사이폰의 작동 특성 연구...102
• 2.5 Micro/Miniature Heat Pipe 열성능 최적화...106
• 3.3 최첨단 측정 기술...122
• 3.1 SRS를 이용한 연소가스의 온도분포 측정기술 개발...122
• 3.2 레이저를 이용한 열전달계수 측정기술 개발...132
• 3.3 Micro-thermal Sensor Array 개발...139
• 3.4 Micro Temperature Sensor Array (MTSA) 개발...144
• 제4장 목표달성도 및 관련분야에의 기여도...152
• 제5장 연구개발결과의 활용계획...153
• 제6장 연구개발과정에서 수집한 해외과학기술정보...154
• 제7장 참고문헌...156