Sun Chao, Zhou Quan, Xia Ke-Qing
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Phys Rev Lett. 2006 Oct 6;97(14):144504. doi: 10.1103/PhysRevLett.97.144504. Epub 2006 Oct 3.
Direct multipoint measurements of the velocity and temperature fields have been made in a turbulent Rayleigh-Bénard convection cell. In the central region of the cell it is found that both velocity and temperature exhibit the same scaling behavior that one would find for the velocity and for a passive scalar in homogeneous and isotropic Navier-Stokes turbulence. This is despite the fact that energy is pumped into the system vertically via buoyancy. Near the cell's sidewall where thermal plumes abound, vertical velocity and temperature exhibit different scalings. A model that takes into account both buoyancy and energy dissipation is proposed and its predictions agree well with the sidewall experimental results.
在一个湍流瑞利 - 贝纳德对流槽中进行了速度场和温度场的直接多点测量。在对流槽的中心区域，发现速度和温度呈现出与均匀各向同性纳维 - 斯托克斯湍流中速度和被动标量相同的标度行为。尽管能量是通过浮力垂直注入系统的，但情况依然如此。在对流槽侧壁附近，热羽流大量存在，垂直速度和温度呈现出不同的标度。提出了一个同时考虑浮力和能量耗散的模型，其预测结果与侧壁实验结果吻合良好。
