Numerical research for the effect of magnetic field on convective transport process of molten salt in Rayleigh-Bénard system
Numerical research for the effect of magnetic field on convective transport process of molten salt in Rayleigh-Bénard system
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DOI：
10.1016/j.ijthermalsci.2023.108605
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发表时间：
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影响因子：
4.5
通讯作者：
Pan-Xin Li;Xiao-Hong Luo;Lu Chen;Jiayin Song;Ben-Wen Li;C. Karcher
中科院分区：
文献类型：
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作者：
Pan-Xin Li;Xiao-Hong Luo;Lu Chen;Jiayin Song;Ben-Wen Li;C. Karcher
采用直接数值模拟的方法研究了外加磁场对导电熔盐封闭腔内Rayleigh-Bénard对流传热和动量传递的影响。这种布置在来自可再生资源的热能存储系统的背景下具有强烈的兴趣。为了离散控制方程，Chebyshev配置谱方法。在5000≤ Ra ≤ 106，5≤ Pr≤ 20和0≤ Ha ≤ 150的情况下，得到了一系列数值结果.首先，我们进行了二维数值模拟，研究了无磁场和有磁场时Pr的影响，发现Pr对热量和动量传递的影响很小。然后，取Pr为定值7，考虑Ra和Ha的影响，进行了二维和三维直接数值模拟。从二维和三维的数值结果，我们得出结论，热和动量传递增强Ra在Ha= 0和流体运动是由磁场稳定在Ha 0。在一定的Ra和Ha值范围内，揭示了更多的传热和流动现象，给出了无磁场条件下Rayleigh-Bénard对流的Nu <$Ra，Nu <$Re和有磁场条件下Rayleigh-Bénard对流的Nu <$Ra Ha和Re <$Ra Ha的标度关联式.
The effects of external applied magnetic field on heat and momentum transfer of Rayleigh-Bénard convection in a closed cavity filled with electrically conductive molten salt are investigated by direct numerical simulation. Such arrangements are of strong interest in the context of thermal energy storage systems from renewable resources. To discretize the governing equations, the Chebyshev collocation spectral method is developed. A series of numerical results for 5000≤ R a≤ 10 6, 5≤ Pr≤ 20 and 0≤ H a≤ 150 are obtained. First, we conduct two-dimensional numerical simulations to investigate the effect of Pr without and with magnetic field and find that Pr has little influence on heat and momentum transfer. Then, taking Pr as a fixed value of 7 and considering the effects ofRa and Ha, 2D and 3D direct numerical simulations are conducted. From both 2D and 3D numerical results, we conclude that, the heat and momentum transfer are enhanced with Ra at Ha= 0 and the fluid motion is stabilized by magnetic field at Ha 0. More phenomena of heat transfer and fluid flow, together with scaling correlations of N u∼ R a, N u∼ R e for Rayleigh-Bénard convection without magnetic field, and, N u∼ R a H a and R e∼ R a H a for Rayleigh-Bénard convection with magnetic field, are revealed under specified ranges of Ra and Ha.