Thermal boundary layer structure in low-Prandtl-number turbulent convection
نویسندگان
چکیده
Abstract
منابع مشابه
Spatial structure of the thermal boundary layer in turbulent convection
We have measured the mean temperature profiles T̄(z) and the thermal layer thickness d th(x ,y) at various horizontal positions on the lower plate of a cylindrical convection cell, using water as the working fluid. The Rayleigh number Ra in the experiment varied from 2310 to 2310. The normalized vertical temperature profiles measured at various positions x along the direction of large scale circ...
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A model for homogeneous anisotropic incompressible turbulence is proposed. The model generalizes the GISS model of homogeneous isotropic turbulence; the generalization involves the solution of the GISS equations along a set of integration paths in wavenumber (k-) space. In order to make the problem tractable, these integration paths (“cascade lines”) must be chosen in such a way that the behavi...
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The Prandtl and Rayleigh number dependences of the Reynolds number in turbulent thermal convection following from the unifying theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000); Phys. Rev. Lett. 86, 3316 (2001)] are presented and compared with various recent experimental findings. This dependence Re(Ra,Pr) is more complicated than a simple global power law. For Pr=5.5 and 10(8)<Ra<10...
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We report a new thermal boundary layer equation for turbulent Rayleigh-Bénard convection for Prandtl number Pr>1 that takes into account the effect of turbulent fluctuations. These fluctuations are neglected in existing equations, which are based on steady-state and laminar assumptions. Using this new equation, we derive analytically the mean temperature profiles in two limits: (a) Pr≳1 and (b)...
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We present Particle Image Velocimetry measurements in the boundary layer in turbulent Rayleigh-Bénard (RB) convection for the Rayleigh number RR = 1.4 × 1010 and the Prandtl number PP = 0.7 . The measurements have been undertaken in a large-scale RB experiment 7.15 m in diameter and 6.30 m in height which is called the “Barrel of Ilmenau”. They give detailed insight into the near-wall flow fiel...
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ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2021
ISSN: ['0022-1120', '1469-7645']
DOI: https://doi.org/10.1017/jfm.2020.961