Thermal Boundary Layer Equation for Turbulent Rayleigh-Benard Convection
Thermal Boundary Layer Equation for Turbulent Rayleigh-Benard Convection
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DOI：
10.1103/physrevlett.114.114302
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发表时间：
2015-03-20
影响因子：
8.6
通讯作者：
Ching, Emily S. C.
中科院分区：
文献类型：
--
作者：
Shishkina, Olga;Horn, Susanne;Ching, Emily S. C.
本文提出了一个新的湍流Rayleigh-Benard对流的热边界层方程，其中Prandtl数Pr > 1，该方程考虑了湍流脉动的影响。这些波动被忽略在现有的方程，这是基于稳态和层流假设。利用这个新的方程，我们推导出解析的平均温度分布在两个极限：（a）Pr大于或接近1和（B）Pr >> 1。这两个理论预测与我们的直接数值模拟的结果非常一致，分别为Pr = 4.38（水）和Pr = 2547.9（甘油）。
We report a new thermal boundary layer equation for turbulent Rayleigh-Benard convection for Prandtl number Pr > 1 that takes into account the effect of turbulent fluctuations. These fluctuations are neglected in existing equations, which are based on steady-state and laminar assumptions. Using this new equation, we derive analytically the mean temperature profiles in two limits: (a) Pr greater than or similar to 1 and (b) Pr >> 1. These two theoretical predictions are in excellent agreement with the results of our direct numerical simulations for Pr = 4.38 (water) and Pr = 2547.9 (glycerol), respectively.