Turbulent convection with "disconnected” top and bottom boundary layers
Department of Physics, The Chinese University of Hong Kong
Shatin, New Territories, Hong Kong, China
Accepted: 5 February 1999
We have done an experimental study of turbulent thermal convection in water using a cell with a baffle placed at its mid-height, over a range of that spans from to . It was found that in this case the large-scale circulation is not able to advect heat between the top and bottom plates and heat has to be carried across the baffle mainly by thermal plumes. Furthermore, the measured still scales with with an exponent consistent with "2/7” for Ra. For below this value, the scaling of with is more consistent with an exponent of "1/3”. The measured temperature PDFs also show signatures of "soft" and "hard" turbulence below and above Ra, respectively.
PACS: 47.27.-i – Turbulent flows, convection, and heat transfer / 47.27.Te – Convection and heat transfer / 44.25.+f – Natural convection
© EDP Sciences, 1999