Direct numerical simulation of turbulent thermal boundary layers
Direct numerical simulation of turbulent thermal boundary layers
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DOI：
10.1063/1.1287912
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发表时间：
2000-10-01
影响因子：
4.6
通讯作者：
Lee, JS
中科院分区：
文献类型：
--
作者：
Kong, H;Choi, H;Lee, JS
本文提出了一种在计算入口处产生真实湍流温度波动的方法，并对在等温和等流壁边界条件的平板上形成的湍流热边界层进行了直接数值模拟。基于自由流速度和入口动量厚度以及 0.71 的普朗特数，使用具有 352x64x128 网格、雷诺数为 300 的完全隐式分数阶方法对控制方程进行积分。计算出的等温壁和等通量壁的斯坦顿数与幂律关系非常吻合，没有来自入口的瞬态区域。平均统计量包括均方根温度波动、湍流热通量、湍流普朗特数以及温度波动的偏度和平坦度与现有的实验和数值数据非常吻合。进行象限分析来研究速度和温度波动之间的相干性。结果表明，壁面法向热通量的行为与雷诺剪应力的行为相似，表明流向速度与温度之间存在密切相关性。还讨论了壁面不同热边界条件对近壁湍流统计的影响。 (C) 2000 年美国物理研究所。 [S1070-6631(00)50510-8]。
In this paper, a method of generating realistic turbulent temperature fluctuations at a computational inlet is proposed and direct numerical simulations of turbulent thermal boundary layers developing on a flat plate with isothermal and isoflux wall boundary conditions are carried out. Governing equations are integrated using a fully implicit fractional-step method with 352x64x128 grids for the Reynolds number of 300, based on the free-stream velocity and the inlet momentum thickness, and the Prandtl number of 0.71. The computed Stanton numbers for the isothermal and isoflux walls are in good agreement with power-law relations without transient region from the inlet. The mean statistical quantities including root-mean-square temperature fluctuations, turbulent heat fluxes, turbulent Prandtl number, and skewness and flatness of temperature fluctuations agree well with existing experimental and numerical data. A quadrant analysis is performed to investigate the coherence between the velocity and temperature fluctuations. It is shown that the behavior of the wall-normal heat flux is similar to that of the Reynolds shear stress, indicating close correlation between the streamwise velocity and temperature. The effect of different thermal boundary conditions at the wall on the near-wall turbulence statistics is also discussed. (C) 2000 American Institute of Physics. [S1070-6631(00)50510-8].