施文彬臺灣大學:機械工程學研究所李俊霖Lee, Chun-LinChun-LinLee2010-06-302018-06-282010-06-302018-06-282009U0001-1008200913300600http://ntur.lib.ntu.edu.tw//handle/246246/187190本篇文章提出了V型微流道的研究及其在可撓式微熱管的應用。V型微流道是以聚氨酯(PU)在矽模上進行圖型轉移製作而成。而矽模則是以曝光顯影搭配定向蝕刻產生共軛V型槽於矽晶元上。而此V型流道在微熱管中是應用於毛細結構。整個可撓式微熱管是以聚氨酯(PU)構成，此外在蒸發及冷凝端加入具有立方結構的鋁片增加熱傳遞的效果，也增加與聚氨酯結構的接觸面積，提升附著的效果。為了使微熱管可以正常運作，測量了不同流體在聚氨酯試片上的接觸角，以及進行了不同流體的毛細測試來評估其抵抗重力的能力。而甲醇被選為適合的工作流體，並且進行了在V型微流道中的毛細蒸發測試，在有加熱源的情況下針對了不同傾斜角度量測其所能爬升的高度。This work presents the investigations of the V-shaped microchannels and its application on the flexible micro heat pipe. The V-shaped microchannel structure is fabricated by polyurethane (PU) from pattern transfer. The lithography and orientation dependent etching is applied to silicon substrate to fabricate the mold with conjugated V-shape grooves. The whole flexible micro heat pipe is composed of PU structure, and the microchannel structure is applied to the micro heat pipe as the wick section. In addition, the aluminum plates with cubic structure are embedded in the micro heat pipe to increase the heat transfer ability at the condenser and evaporator. The design of the cubic structure could increase the contact area which enhanced the bonding with the polyurethane structure. To find the adequate working fluid, the contact angle of different fluids are measured and capillary test are applied. And the different criterions are also utilized. The methanol is chosen as the adequate working fluid. And the capillary evaporation is applied to the V-shaped microchannel structure with methanol as the testing fluid to measure the dry-out length under different tilting angles.誌謝 I要 IIbstract IIIable of Contents IVist of Figures VIIist of Tables IXist of Appendix Figure Xist of Appendix Tables Xomenclature XIIreek Alphabet XIIIhapter 1. Introduction 1.1. Introduction of the heat pipe 1.2. Introduction of the micro heat pipe 4.3. Literature review 5.4. Research purpose of our micro heat pipe 18hapter 2. Principle and Theoretical Analysis of Micro Heat Pipes 20.1. Micro heat pipe operating principle 20.2. Concus-Finn condition 23.3. Operation limit 24.3.1. Capillary limit 25.3.1.1. Capillary pressure 26.3.1.2. Vapor pressure drop 29.3.1.3. Liquid pressure drop 29.3.1.4. Hydrostatic pressure 31.3.2. Entrainment limit 32.3.3. Boiling limit 33.3.4. Sonic limit 34.4. Thermal resistance 34.5. Thermal conductivity 37.6. Working fluid 37.6.1. Figure of merit 37.7. Capillary evaporation performance of V-shaped microgrooves 39hapter 3. Design and Fabrication of Micro Heat Pipe 42.1. Design of flexible micro heat pipe 42.2. Material of the flexible micro heat pipe 45.2.1. Polymer material -- Polyurethane 45.2.2. Aluminum plate 46.3. Fabrication of the micro heat pipes 48.3.1. Fabrication of the mold 49.3.2. Fabrication of the PU wick structure 54.3.3. Fabrication of the cover layer 57.3.4. Sealing process 58hapter 4. Experimental Setup 60.1. Contact angle measurement 60.2. Heat conductance of the PU structure 62.3. Capillary test of the V-shaped groove 64.4. Capillary evaporation performance of the micro grooves 66hapter 5. Result and Discussion 69.1. Contact angle measurement and Concus-Finn condition 69.2. Heat conductance of the PU structure 71.3. Capillary test of the V-shaped groove 72.4. Capillary evaporation performance of the micro grooves 74.5. Consideration of the design of the micro heat pipe 78.5.1. Polyurethane micro heat pipe 78.5.2. Effect of the embedded aluminum plates 78.5.3. Methanol in the polyurethane micro heat pipe 80hapter 6. Conclusion and Future Work 82.1 Conclusion 82.2 Future work 83ppendix 851. Pattern transfer with PDMS mold 852. Fabricaton and characterization of porous polymeric composites of PDMS and nylon for flexible heat pipe 88bstract 882.1. Introduction 892.2 Principle 932.3 Material and method 942.4 Fabrication 962.4.1 Fabrication of porous material 962.4.2 Sample fabrication 982.4.3 Heat pipe 982.5. Result and discussion 1012.5.1 Compression test 1012.5.2 Porosity 1032.5.3 Absorption test 1042.5.3.1 III-series 1052.5.3.2 IV-series 1082.5.3.3Absorbing velocity 1112.6. Conclusion 112eference 113utobiography 1172035770 bytesapplication/pdfen-US可撓式微熱管V型微流道聚氨酯圖型轉移毛細蒸發毛細結構flexible micro heat pipeV-shaped microchannelspolyurethanepattern transfercapillary evaporationwick structurethesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/187190/1/ntu-98-R96522534-1.pdf