Thu July 10th 2008
Seminar Origin of the Temperature Oscillation and Flow Dynamics in Turbulent Thermal Convection
Ke-Qing Xia


In this talk I will present our recent experimental study of the three-dimensional spatial structure of the temperature oscillations in a cylindrical Rayleigh-Benard (RB) convection cell of aspect ratio one. It is found that the thermal plumes are not emitted periodically, but continuously and randomly, from the top and bottom plates. We further found that the low frequency oscillation of the temperature filed does not originate from boundary layers, but rather is a result of the horizontal motion of the hot ascending and cold descending fluids being modulated by the twisting and sloshing motion of the bulk flow field. Evidence will also be presented to show that the bulk sloshing mode of the flow field near cell center is a manifestation of twisting motion of fluid near the top and bottom plates and that all velocity and temperature oscillations in the RB system originate from the twisting motion.
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The 10th Complex Motion in Fluids 2021
Max Planck Gesellschaft
Centre for Scientific Computing