本文以數值模擬以及實驗結果來探討物理模型為一具上移動壁面之矩形容器內含有相變化材料 ( PCM ) 之熱控制動器中熱流現象的變化。其工作原理是利用相變化材料在融解過程固液相密度差造成體積膨脹的特性，來推動上移動壁面的上升，進而達到制動的目的。在數值模擬方面所考慮參數之範圍如下：高寬比為2、3、4、6與12，Pr=41.7，Ste=0.1、0.3與0.5，Sc=0， 。模擬結果顯示，萊利數對上移動壁面之位移及加熱壁平均紐賽數之影響隨容器之高寬比提昇而大幅減弱。在高寬比為12情況下，上移動壁面位移之數值預測值與一維熱傳導解析解值之平均誤差量僅為3.1%。另外，在寬寬比為12之矩形容器實驗所測得上移壁面位移量略低於相對應之數值預測。

　　Results of an experimental and numerical investigation on thermal-fluid characteristics of a phase-change-material ( PCM ) thermal actuator consisting of a rectangular enclosure with a moveable upper wall are reported. The working principle of thermal actuator is utilizing volume change associated with melting process of the PCM. The parameters considered in the simulation are as follows：Asp = 2,3,4,6 and 12；Pr=41.7；Ste=0.1,0.3 and 0.5；Sc=0； . Simulation results reveal that the little influence of Rayleigh number on the displacement of upper moveable wall and the average Nusselt number of heated wall of the rectangular enclosure tends to degrade greatly with the increase of the aspect ratio. The numerical results of the displacement of the upper movableof the enclosure during melting process are found to be quite close to those predicted from the one-dimensional conduction analytical analysis. Moreover, in comparison with the experimental data for a rectangular enclosure of aspect ratio 12, the numerical results for the displacement of the upper movable wall appear somewhat overpredicted.

Benard, C., Gobin, D., and Zanoli, A., “Moving Boundary Problem: Heat Conduction in the Solid Phase of a Phase-Change Material During Melting Driven by Natural Convection in the Liquid”, Int. J. Heat Mass Transfer, Vol. 29, No. 11, pp. 1669-1681, 1986.
Giangi, M., Stella, F., and Kowalewski, T. A., “Phase Change Problems with Free Convection：Fixed Grid Numerical Simulation”, Computing and Visualization in Science, Vol. 2, pp.123-130, 1999.
Hale, N. W., Jr., and Viskanta, R., “Photographic Observation of the Solid-Liquid Interface Motion During Melting of a Solid Heated From an Isothermal Vertical Wall”, Letters in Heat and Mass Transfer, Vol. 5, pp. 329-337, 1978.
Hamcan, M. A., and Elwerr, F. A., “Thermal energy storage using a phase change material”, Solar Energy, Vol. 56, No. 2, pp. 183-189,1996.
Ho, C. J., “Solid-liquid phase change heat transfer in enclosure”, Ph.D Dissertation, Purdue University, 1982.
Ho, C. J., and Viskanta, R. “Heat transfer during melting from an isothermal vertical wall.” J. Heat Transfer, Vol. 106, pp. 12-19, 1984
Jany, P., and Bejan, A., ”Scaling Theory of Melting with Natural Convection in an enclosure”, Int. J. Heat Mass Transfer. Vol. 31,No. 6, pp. 1221-1235, 1988.
Kim, C. J., and Kaviany, M., “A Numerical Method for Phase-Change Problems with Convection and Diffusion”, Int. J. Heat Mass Transfer, Vol. 35, No. 2, pp. 457-467, 1992.
Laouadi, A., Lacroix, M., and Galanis, N., “A Numerical Method for the
Treatment of Discontinuous Thermal Conductivity in Phase-Change Problems”, Int. J. Numerical Methods for Heat & Fluid Flow, Vol. 8, No. 3, pp. 265-287, 1998.
Laouadi, A., and Lacroix, M., “Thermal Performance of a Latent Heat Energy Storage Ventilated Panel for Electric Load Management”, Int. J. Heat and Mass Transfer, Vol. 42, pp. 275-286, 1999.
Lu, T. J., “Thermal Management of High Power Electronics with Phase-Change Cooling”, Int. J. Heat and Mass Transfer, Vol. 43, pp. 2245-2256, 2000.
Rubio, O., Bravo, E., and Claeyssen, J. R., “Thermally Driven Cavity Flow with Neumann Condition for the Pressure”, Applied Numerical Mathematics, Vol. 40, pp.327-336, 2002.
Samarskii, A. A., Vabishchevich, P. N., Iliev, O. P., and Churbanov, A. G., “Numerical Simulation of Convection/Diffusion Phase Change Problems-a Review”, Int. J. Heat Mass Transfer, Vol. 36, No.17, pp. 4095-4106, 1993.
Wang, Y., Amiri, A., Vafai, K., “An experimental investigation of the melting process in a rectangular enclosure”, Int. J. Heat and Mass Transfer, Vol. 42, pp. 3659-3672, 1999.
Yoo, H., and Ro, S. T., “Melting Pricess with Solid-Liquid Density Change and Natural Convection in a Rectangular Cavity”, Int. J. Heat and Fluid Flow, Vol. 12, No. 4, December 1991.
Zhang, Z., and Bejan, A., “Melting in an Enclosure Heated at Constant Rate”, Int. J. Heat Mass Transfer. Vol. 32, No. 6, pp. 1063-1076, 1989.
Zhang, Z., and Bejan, A., “The Problem of Time-Dependent Natural Convection Melting with Conduction in the Solid”, Int. J. Heat Mass Transfer, Vol. 32, No. 12, pp. 2447-2457, 1989.
葉長泰，矩形容器內冰熔解熱流現象影響之研究-高萊利數之結果，成功大學機械系研究所碩士論文，1996。
王文傑，具可移動壁面之矩形容器內熔解熱傳現象之實驗研究，成功大學機械系研究所碩士論文，2000。
林子成，具一移動壁面之矩形容器內融化過程熱流現象之數值模擬，成功大學機械系研究所碩士論文，2001。