Scaling laws in turbulent Rayleigh-Benard convection under different geometry

A systematic study of turbulent Rayleigh-Benard convection is carried out in two horizontal cylindrical cells of different lengths filled with water. Global heat transport and local temperature and velocity measurements are made over varying Rayleigh numbers Ra. The scaling behavior of the measured Nusselt number Nu(Ra) and the Reynolds number Re(Ra) associated with the large-scale circulation remains the same as that in the upright cylinders. The scaling exponent for the rms value of local temperature fluctuations, however, is strongly influenced by the aspect ratio and shape of the convection cell. The experiment clearly reveals the important roles played by the cell geometry in determining the scaling properties of convective turbulence. Copyright (C) EPLA, 2010