对于旋转对流的热传递增强的临界普兰特尔数
1Department of Mechanical Engineering, Indian Institute of Technology, Kanpur 208016, India.
Physical review letters
|February 2, 2024
概括
旋转增强了雷利-贝纳德对流 (RBC) 中的热传递,通过埃克曼的. 最佳的热传递发生在特定的普兰特尔和泰勒数下,这些数字随着雷利数的增加而增加.
科学领域:
- 流体动力学 流体动力学
- 热传递是一种热传递.
- 交流是指对流的交流.
背景情况:
- 雷利-贝纳德对流 (RBC) 是一个基本的流体动力学问题.
- 旋转可以稳定流体流动,并影响传热效率.
- 埃克曼是旋转影响对流的关键机制.
研究的目的:
- 为了全面分析旋转RBC中的传热增强.
- 研究雷利数 (Ra),普兰特尔数 (Pr) 和泰勒数 (Ta) 对传热的影响.
- 为了确定增强热传输的关键和最佳参数.
主要方法:
- 对旋转的红细胞进行了直接的数值模拟 (DNS).
- 该研究在一个定义的参数空间内系统地改变了Ra,Pr和Ta.
- 量化了热传递,并比较了旋转和非旋转的情况.
主要成果:
- 确定了一个关键的普兰特尔数 (Pr_{cr}),低于这个数值,旋转不会提供显著的热传递增强.
- 为了最大的热传递增强,发现了最佳的普兰特尔数 (Pr_{opt}) 和最佳的泰勒数 (Ta_{opt}).
- 关键/最佳参数和增强程度都随着Ra的增加而增加.
- 在Ra=2×10^{10}之前观察到显著的增强.
结论:
- 旋转显著增强RBC中的热传递,特别是在更高的雷利数时.
- 普兰特尔数起着至关重要的作用,具有最大化传热的特定最佳值.
- 预计在更高的Ra下,热传递增强的进一步增加将与Pr的相应增加相对应.
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