Understanding the reversal process of the large-scale circulation will facilitate system recognition of turbulent penetrative Rayleigh-Bénard convection. The present work describes experimental and numerical investigations on the Rayleigh-Bénard flow of water near 4 °C in a box-shaped container. The results indicate that the revised Nusselt number is slightly higher than average Nusselt number with adiabatic assumption. The Nusselt numbers from the simulations show good agreement with the experiment values. Large-scale circulation reversal becomes less likely with the increasing Rayleigh number and density inversion parameter. Reversal is not observed at large density inversion parameters and Rayleigh numbers. Large vertical velocity and temperature fluctuations at the center point are found during the reversal process. However, the Nusselt number is slightly affected by the occurrence of the reversal.

中文翻译：

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箱形容器中 4 °C 附近湍流贯穿性 Rayleigh-Bénard 流的实验和数值研究


了解大尺度环流的反转过程将有助于系统识别湍流穿透性 Rayleigh-Bénard 对流。本工作描述了对箱形容器中 4 °C 附近 Rayleigh-Bénard 水流的实验和数值研究。结果表明，修正后的努塞尔数略高于绝热假设的平均努塞尔数。模拟中的努塞尔数与试验值吻合较好。随着 Rayleigh 数和密度反转参数的增加，大规模环流逆转的可能性变得较小。在大密度反转参数和 Rayleigh 数下未观察到反转。在反转过程中，在中心点发现较大的垂直速度和温度波动。但是，努塞尔数受反转的发生略有影响。