抄録
The fluid flow and heat transfer of the natural convection in a horizontal water layer, with heated from below and cooled from above, using water as the working fluid, were investigated experimentally. An experiment was performed for the Rayleigh number (Ra) in the range of 10^8 up to 10^<11>. At Ra>10^7, turbulent large-scale flow was gradually replaced by rising and sinking plumes. As Ra increases further, plumes changed into a three-dimensional vortex which is new flow patterns appeared at high Rayleigh numbers. The three-dimensional vortex released from the thermal boundary layer rapidly mixed with the fluid and transferred a large quantity of the heat to the upper part of the water layer.
