Dresden 2017 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 16: Focus: Fundamental aspects of turbulent convection
DY 16.5: Vortrag
Dienstag, 21. März 2017, 10:45–11:00, ZEU 118
Numerical studies of turbulent convection in liquid mercury and sodium — •Jörg Schumacher1 and Janet D. Scheel2 — 1TU Ilmenau, Germany — 2Occidental College Los Angeles, USA
Statistical properties of turbulent Rayleigh-Bénard convection at low Prandtl numbers Pr, which are typical for liquid metals such as mercury or gallium at Pr=0.021 and liquid sodium at Pr=0.005, are investigated in high-resolution, three-dimensional and massively parallel spectral element simulations in a closed cylindrical cell with an aspect ratio of one. These results are compared to previous turbulent convection simulations in air. In detail, we compare the scaling of global momentum and heat transfer with existing experiments or other simulations. Low-Prandtl-number flows are characterized by a significantly enhanced momentum transfer compared to convection in air. Thus we also investigate the dynamics of near-wall structures in the transient velocity boundary layers of this class of convection flows and their connection to critical points of the skin friction field. These findings are related to turbulent boundary layers in channel flows without temperature differences.