Abstract This work investigates the effects of a rotating rough cylinder within a square cavity on the natural convective heat transfer process. Six different cases consist of case 1 (cavity without a cylinder), case 2 (cavity with a rotating smooth cylinder), case 3 (cavity with a rotating rough cylinder having one roughness component), case 4 (cavity with a rotating rough cylinder having two roughness components), case 5 (cavity with a rotating rough cylinder having three roughness components), and case 6 (cavity with a rotating rough cylinder having four roughness components) are computed under various parameters such as the Rayleigh numbers (Ra) in the range from 103 to 106, radius ratios (R) of 0.1, 0.2, and 0.3, and non-dimensional rotating speeds (RS) between −1000 and 1000. It is found that the difference between the cases is more evident at lower Rayleigh numbers and higher rotating speeds. In addition, under effective Rayleigh numbers (Ra = 103 and 104), the rate of the heat transfer is maximum in case 2 regardless of the rotating speed and radius ratio. Beyond case 2, case 5 presents the highest heat transfer rate. The maximum heat transfer enhancement occurs in case 2 with 252% under Ra = 103, R = 0.3, and RS = −1000.

中文翻译：

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存在具有特定粗糙度分量的旋转圆柱体时方腔中的自然对流分析

摘要 这项工作研究了方腔内旋转粗糙圆柱体对自然对流传热过程的影响。六个不同的案例包括案例 1（没有圆柱体的腔体）、案例 2（带有旋转光滑圆柱体的腔体）、案例 3（带有一个粗糙度分量的旋转粗糙圆柱体的腔体）、案例 4（带有旋转粗糙圆柱体的腔体）两个粗糙度分量）、情况 5（具有三个粗糙度分量的旋转粗糙圆柱体的腔体）和情况 6（具有四个粗糙度分量的旋转粗糙圆柱体的腔体）是在各种参数下计算的，例如中的瑞利数 (Ra)范围从 103 到 106，半径比 (R) 为 0.1、0.2 和 0.3，无量纲转速 (RS) 介于 -1000 和 1000 之间。发现在较低的瑞利数和较高的转速下，情况之间的差异更加明显。此外，在有效瑞利数下（Ra = 103 和 104），无论转速和半径比如何，情况 2 的传热速率都是最大的。除了案例 2，案例 5 呈现出最高的传热率。在 Ra = 103、R = 0.3 和 RS = -1000 下，最大传热增强发生在情况 2 中，为 252%。