微熱管主要是應用於電子晶片中，利用內部填充工作流體的相變化來導熱，使晶片溫度較為平均。在本研究中我們為建立V型溝槽微熱管的熱傳模型，並利用微擾法找出邊界層內與邊界層外的質量、動量、能量守恆式和Young-Laplace方程式，並將其作展開，藉此以得到流場與溫度場的近似解，進而很清楚的描述出微熱管的工作原理以及流體的行為。同時我們也再利用數值解來做驗證，並計算近似解不適用時之微熱管性能。利用所建立的模型來預測在不同設計條件下的最大熱傳量及溫度分布，我們發現最大熱傳量會先隨著溝槽開口角度增加而因可填充工作流體增加隨之增加，但增加至一定程度時又會隨著溝槽開口角度增加時毛細力下降而減少。除此之外，最大熱傳量也會隨著熱管管長越短，溝槽深度越深而增加，但基材熱端的溫度也會隨之上升。因此我們可藉由分析結果，依照不同的需求來找出最恰當的設計。而在基材冷端溫度固定，但液態工作流體具有不同散熱條件下的分析中，也發現熱管藉由相變化所傳遞的熱量遠遠大於藉由熱傳導所傳遞的熱量，因此即使有較好的對流條件，熱管性能提升的效果依舊並不顯著。
關鍵字：微熱管

Micro heat pipes can be used to facilitate heat removal from electronic chips and render the temperature distribution thereon more uniform. In this work, we construct a one-dimensional model, which accounts for the mass, momentum, and energy balance in a micro heat pipe, and use it to calculate the performance characteristics of the heat pipe. As it turns out, the temperature and flow fields in a micro heat pipe usually would develop boundary-layer structures. Perturbation analysis therefore is carried out to resolve such structures, and to obtain asymptotic solutions for the temperature and flow fields. Moreover, numerical computations are carried out to explore the system parameter regime in which the asymptotic results are invalidated. The results indicate that, as the apex angle of the micro channel in the heat pipe increases, the critical heat input (causing dry-out of the micro heat pipe) increases first because of the increased amount of working liquid filled in the heat pipe. But if the apex angle exceeds a particular value, the critical heat input would start to decrease, because the corresponding decrease in the meniscus curvature of the working liquid would reduce the capillary force that drives the working liquid flow. Meanwhile, the critical heat input increases with decreasing heat-pipe length and with increasing micro-channel depth. The effects of various external heat transfer conditions on the performance of heat pipes also are examined, and it is concluded that the heat transport in a micro heat pipe mainly is through the phase change of the working liquid, rather than through conduction.
Key words : micro heat pipe

[1] Suman, B. 2007.Modeling, Experiment,and Fabrication of micro-Grooved Heat Pipe:An Update. J. ASME Vol. 60,107-119.
[2]日本熱管技術協會編, 依日光譯, 1986, 熱管技術理論實務(HEAT PIPE TECHNOLOGY). 復漢出版社
[3] Cotter, T.P., 1984. Principles and prospects of micro heat pipes. In: Proceedings of the Fifth Int. Heat pipe Conference, Tsukuba, Japan, pp.328-332.
[4] Babin, B. R., Peterson, G. P., Wu. D., 1990, Steady state modeling and testing of a micro heat pipe. J. Heat Transfer 112,595-601.
[5] Wu, D., Peterson, G.P., 1991. Investigation of the transient thermodynamics of micro heat pipe. J. Heat Transfer 112, 595-601.
[6] Swanson, L. W., Peterson, G. P., 1995. The interfacial thermodynamics of micre heat pipes. J. Heat Transfer 115, 195-201.
[7] Xu, X., Carey, V. P.,1990. Evaporation from microgrooved surface-an approximate heat transfer model and its comparison with experimental data. J. Thermophys. 4, 512-520.
[8] Stephan, P. C., Busse, C. A., 1992. Analysis of heat transfer coefficient of grooved heat pipe evaporator walls. Int. J. Heat Mass Transfer 35, 383-391.
[9] Khrustalev, D., Faghri, A., 1994. Thermal analysis of a micro heat pipe. J. Heat transfer 116, 189-198.
[10] Longtin, J. P., Badran, B., Gerner, F. M., 1994. A One-Dimensional Model of a Micro Heat Pipe During Steady-State Operation. J. Heat Transfer, Vol. 116, pp. 709-715.
[11] Peterson, G. P., Ma, H. B., 1996. Theoretical analysis of the maximum heat transport in triangular grooves: a study od idealized micro heat pipe. J. Heat Transfer 188, 731-739.
[12] Suman, B., De, S., DasGupta, S., 2005. A model of the capillary limit of a micro heat pipe and prediction of dry-out length. Int. J. Heat Fluid Flow 26, 495-505.
[13] Anand, S., De, S., DasGupta, S., 2002. Experimental and theoretical study of axial dryout point for evaporation from V-shaped microgrooves. Int. J. Heat Mass Transfer 45, 1535-1543.
[14] Suman, B., De, S., DasGupta, S., 2005. Transient modeling of micro-grooved heat pipe. Int. J. Heat Mass Transfer 48, 1633-1646.
[15] Suman, B., Hoda, N., 2005.Effect of Variations in thermophysical properties and design parameters on the performance of a V-Shaped micro grooved heat pipe. Int. J. Heat Mass Transfer 48, 22090-2101.
[16] Suman, B., De, S., DasGupta, S., 2006. On the Fill Charge and the Sensitivity Analysis of a V-Shaped Micro Heat Pipe J. AIChE Vol. 52,No. 9, 3041-3053.
[17] Longtin, J.P.,Badran, B.,Gerner, F.M. A One-Dimensional Model of a Micro Heat Pipe During Steady-State Operation. J. ASME ol.116,709-715.
[18] 郭伯軒,微熱管熱傳性能之數值分析,國立成功大學機械工程所,碩士論文,2008.
[19] Yew, M.H., Kek, K.T., 2010. Analysis of Microheat Pipes With Axial Conduction in the Solid Wall J. ASME vol. 132,071301-0713011.
[20] Reay, D., Kew P. 2006, Heat Pipes 5nd ed. Butterworth-Heineman
[21] Incropera F.P., 2005,Introduction To HEAT TRANSFER 5nd ed. John Wiley & Sons (Asia) Pte Ltd.