Mashiko Takashi, Tsuji Yoshiyuki, Mizuno Takatoshi, Sano Masaki
Department of Physics, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2004 Mar;69(3 Pt 2):036306. doi: 10.1103/PhysRevE.69.036306. Epub 2004 Mar 31.
Using ultrasonic velocimetry we measured the vertical profile of the velocity fluctuation in high-Rayleigh-number thermal convection in a cell with aspect ratio of 0.5, filled with a low-Prandtl-number fluid, mercury. The intriguing fluctuating dynamics of the mean flow and universal nature of the kinetic energy cascade are elucidated utilizing spectral decomposition and reconstruction. The scaling properties of the structure functions and the energy spectrum are directly calculated without the use of Taylor's frozen-flow hypothesis. Despite the complex nature of the mean flow, it is found that the energy cascade process exhibits universal laws in thermal turbulence.
我们使用超声测速法测量了在一个长宽比为0.5、充满低普朗特数流体汞的单元中，高瑞利数热对流中速度波动的垂直剖面。利用谱分解和重构阐明了平均流有趣的波动动力学和动能级串的普适性质。在不使用泰勒冻结流假设的情况下，直接计算了结构函数和能谱的标度性质。尽管平均流具有复杂的性质，但发现能量级串过程在热湍流中表现出普适规律。
