This paper intends to analyze computationally the rarefied gaseous flow and performance of heat transfer for a steady-state laminar 2D free convection within tilted enclosures where the sided walls are of wavy shape. Low-pressure or rarefied flows are flows with Knudsen number greater than zero. These kinds of flows are of incredible significance in different applications. Boussinesq estimation is adopted to represent the buoyancy effects. Grid independence tests are carried out to ensure accuracy. Moreover, the current code is verified with numerical and experimental results existing in the literature. Flow and thermal fields for simulated cases are presented. The outcome of this research indicates that there is a direct relationship between the average Nusselt number and the Rayleigh number, and a converse relationship between the average Nusselt number and Knudsen number. Additionally, the numerical simulations reveal that increasing the amplitude of the two-sided wavy walls of the enclosure slightly mends the transfer of heat. Besides, it is determined that the tilt angle slightly affects the heat transfer performance of such flows; and it is evident from the simulations that horizontal or nearly horizontal orientations of such cavities give the maximum transfer of heat. Finally, a correlation representing the relationship of the average Nusselt number in terms of all the examined parameters is introduced.

中文翻译：

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斜波侧壁方形腔内稀薄气流的数值研究


本文旨在通过计算分析侧壁为波浪形的倾斜外壳内稳态层流二维自由对流的稀薄气流和传热性能。低压或稀薄流是努森数大于零的流。这些类型的流在不同的应用中具有难以置信的意义。采用 Boussinesq 估计来表示浮力效应。进行网格独立性测试以确保准确性。此外，当前的代码已经通过文献中存在的数值和实验结果进行了验证。给出了模拟案例的流场和热场。这项研究的结果表明，平均努塞尔数与瑞利数之间存在直接关系，而平均努塞尔数与克努森数之间存在相反关系。此外，数值模拟表明，增加外壳两侧波状壁的振幅可以稍微改善热传递。此外，确定倾斜角对此类流动的传热性能影响较小；从模拟中可以明显看出，这种空腔的水平或接近水平方向可实现最大程度的热传递。最后，引入了表示平均努塞尔数与所有检查参数之间关系的相关性。