48,115 research outputs found
Heat transport measurements in turbulent rotating Rayleigh-Benard convection
We present experimental heat transport measurements of turbulent
Rayleigh-B\'{e}nard convection with rotation about a vertical axis. The fluid,
water with Prandtl number () about 6, was confined in a cell which had
a square cross section of 7.3 cm7.3 cm and a height of 9.4 cm. Heat
transport was measured for Rayleigh numbers Ra and Taylor numbers Ta . We show the variation of
normalized heat transport, the Nusselt number, at fixed dimensional rotation
rate , at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed
Rossby number Ro. The scaling of heat transport in the range to about
is roughly 0.29 with a Ro dependent coefficient or equivalently is also
well fit by a combination of power laws of the form .
The range of Ra is not sufficient to differentiate single power law or combined
power law scaling. The overall impact of rotation on heat transport in
turbulent convection is assessed.Comment: 16 pages, 12 figure
Atlantic Ocean Heat Transport Enabled by Indo-Pacific Heat Uptake and Mixing
The ocean transports vast amounts of heat around the planet, helping to regulate regional climate. One important component of this heat transport is the movement of warm water from equatorial regions toward the poles, with colder water flowing in return. Here, we introduce a framework relating meridional heat transport to the diabatic processes of surface forcing and turbulent mixing that move heat across temperature classes. Applied to a (1/4)° global ocean model the framework highlights the role of the tropical Indo‐Pacific in the global ocean heat transport. A large fraction of the northward heat transport in the Atlantic is ultimately sourced from heat uptake in the eastern tropical Pacific. Turbulent mixing moves heat from the warm, shallow Indo‐Pacific circulation to the cold deeper‐reaching Atlantic circulation. Our results underscore a renewed focus on the tropical oceans and their role in global circulation pathways
Simulation of heat transport in low-dimensional oscillator lattices
The study of heat transport in low-dimensional oscillator lattices presents a
formidable challenge. Theoretical efforts have been made trying to reveal the
underlying mechanism of diversified heat transport behaviors. In lack of a
unified rigorous treatment, approximate theories often may embody controversial
predictions. It is therefore of ultimate importance that one can rely on
numerical simulations in the investigation of heat transfer processes in
low-dimensional lattices. The simulation of heat transport using the
non-equilibrium heat bath method and the Green-Kubo method will be introduced.
It is found that one-dimensional (1D), two-dimensional (2D) and
three-dimensional (3D) momentum-conserving nonlinear lattices display power-law
divergent, logarithmic divergent and constant thermal conductivities,
respectively. Next, a novel diffusion method is also introduced. The heat
diffusion theory connects the energy diffusion and heat conduction in a
straightforward manner. This enables one to use the diffusion method to
investigate the objective of heat transport. In addition, it contains
fundamental information about the heat transport process which cannot readily
be gathered otherwise.Comment: Article published in: Thermal transport in low dimensions: From
statistical physics to nanoscale heat transfer, S. Lepri, ed. Lecture Notes
in Physics, vol. 921, pp. 239 - 274, Springer-Verlag, Berlin, Heidelberg, New
York (2016
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