Transitional boundary layers in low-Prandtl-number convection
Transitional boundary layers in low-Prandtl-number convection
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DOI：
10.1103/physrevfluids.1.084402
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发表时间：
2016-12-29
影响因子：
2.7
通讯作者：
Scheel, Janet D.
中科院分区：
文献类型：
--
作者：
Schumacher, Joerg;Bandaru, Vinodh;Scheel, Janet D.
从过渡性和湍流粘性边界层的角度，重新讨论了单位长宽比封闭圆柱体中湍流Rayleigh-Benard流动速度场和温度场的边界层结构。当Rayleigh数足够大时，底板和顶板的动力学可以分为下流羽流的撞击区、上行羽流的喷射区和远离侧壁的内部区域。后者是由大尺度环流(LSC)辊的切变所主导的，它填满了整个单体并不断地改变其取向。工作流体是普朗特数Pr=0.021的液体汞或镓，瑞利数为3×10(5)
The boundary layer structure of the velocity and temperature fields in turbulent Rayleigh-Benard flows in closed cylindrical cells of unit aspect ratio is revisited from a transitional and turbulent viscous boundary layer perspective. When the Rayleigh number is large enough, the dynamics at the bottom and top plates can be separated into an impact region of downwelling plumes, an ejection region of upwelling plumes, and an interior region away from the side walls. The latter is dominated by the shear of the large-scale circulation (LSC) roll, which fills the whole cell and continuously varies its orientation. The working fluid is liquid mercury or gallium at a Prandtl number Pr = 0.021 for Rayleigh numbers 3 x 10(5)