DOI: 10.1615/ICHMT.2015.THMT-15
ISBN Print: 978-1-56700-427-4
ISBN CD: 978-1-56700-428-8
Fine-scale dynamics in turbulent Rayleigh-Benard convection
SINOPSIS
Several features of the small-scale turbulence in Rayleigh-Benard convection have been studied in this work. Namely, the average rates of change in the invariants of the velocity gradient tensor in the bulk region display the classical tear-drop shape. Moreover, the preferential vorticity alignment with the intermediate eigenvector of the rate-of-strain tensor has also been observed. Apart from this classical analysis, we propose to study the dynamics of the traceless part of the gradient of the velocity times temperature. The invariants of the new tensor are more appropriate to study the dynamics of the thermal plumes and the buoyancy production since they highlight zones with both high thermal and kinetic small-scale interactions.