Numerical simulation and experimental verification of constrained melting of phase change material in inclined rectangular enclosures
Numerical simulation and experimental verification of constrained melting of phase change material in inclined rectangular enclosures
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DOI：
10.1016/j.icheatmasstransfer.2017.07.023
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发表时间：
2017-11
影响因子：
7
通讯作者：
B. Kamkari;H. J. Amlashi
中科院分区：
文献类型：
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作者：
B. Kamkari;H. J. Amlashi
本文对相变材料(PCM)在竖直和倾斜矩形封闭腔中的熔化进行了数值研究。数值模拟结果与实验结果的对比表明，相变材料垂直封闭熔化过程的二维数值模拟能够准确地预测相变材料熔融过程中的固-液界面液相分数和时间演化。对倾斜封闭空间(45°和0°)的液体分率瞬时值进行了较好的预测，最大偏差小于6.5%。无论斯蒂芬数如何，0°和45°倾斜封闭空间的完全熔化时间分别比垂直封闭空间缩短约52%和37%。研究发现，倾斜封闭空间内的换热增强和熔化速率的增加是自然对流的加强和反向旋涡产生的热羽形成的结果。此外，为了推广这些结果，引入了一组无量纲数，并用它建立了三个新的关联式，用于预测倾斜封闭空间中的瞬时液体分数、储能和时间平均Nusselt数。
In the present study, melting of phase change material (PCM) in vertical and inclined rectangular enclosures is numerically investigated. Comparison of the numerical and experimental results reveals that the two-dimensional numerical simulations of PCM melting in vertical enclosures can accurately predict both the liquid fraction and the temporal evolution of the solid-liquid interface. Also, it well predicts the instantaneous values of liquid fractions for inclined enclosures (45° and 0°) with a maximum deviation less than 6.5%. Regardless of the Stephan number, the complete melting time in 0° and 45° inclined enclosures are respectively about 52% and 37% shorter as compared to the vertical enclosure. Heat transfer enhancement and consequently melting rate augmentation in inclined enclosures are found to be the result of the intensification of natural convection flows and formation of thermal plumes originating from counter-rotating vortices. Moreover, to generalize the results, a group of dimensionless numbers is introduced and used to develop three new correlations for prediction of the instantaneous liquid fraction, energy storage and time-averaged Nusselt number in inclined enclosures.