We studied thermal turbulence in a low Prandtl number, Pr, fluid using liquid Hg (Pr ­ 0.024). For Rayleigh numbers (106 , Ra , 108), the histogram of temperature fluctuations at the center of the cell (aspect ratio 1), and the scaling laws for the Nusselt number and the large scale flow, all showed He-like hard turbulence. However, the cascade range of the frequency spectrum of the temperature...

We report on turbulent thermal convection of a nematic liquid crystal heated from below in a cylindrical cell with an aspect ratio (diameter/height) equal to 0.500 for Rayleigh numbers 2×10 < ∼ Ra < ∼ 3 × 10. The Nusselt number Nu as a function of Ra did not differ significantly from that of an isotropic fluid. In a vertical magnetic field H we found Nu(H)/Nu(0) = 1 + a(Ra)H with a(Ra) = 0.24Ra...

Measurements of the temperature distribution were performed in the upper (cold) boundary layer of a rectangular Rayleigh-Bénard cell with aspect ratios Gamma(x) = 5 and Gamma(y) = 1 using air with Prandtl number Pr = 0.71 as the working fluid. The range of investigated Rayleigh numbers was from Ra approximately 6 x 10(7) to Ra approximately 6 x 10(8), and the measurements were taken at two diff...

This work seeks to improve understanding of atmospheres in radiative-convective equilibrium. We use two types of idealized, dry radiative-convective models. The first type of model resembles Rayleigh-Benard convection, except that thermal radiative transfer is included. This type of system can be investigated in the laboratory. The second type of model is a more faithful representation of the e...

Onset of Double Diffusive Rayleigh-Benard-Magneto (DDRBM) convection is studied for a double layered system composed incompressible fluid confined by adiabatic rigid peripheries under the governance Local Thermal Non-Equilibrium (LTNE). Result acquired problem obtained analytically through mode Regular Perturbation. Consequence physical factors such as solid phase thermal expansion ratio, diffu...

Abstract: In this paper, natural convection from vertical cylinders with inclined plate fins is investigated experimentally for use in cooling electronic equipment. Extensive experimental investigations are performed for various inclination angles, fin numbers, and base temperatures. From the experimental data, a correlation for estimating the Nusselt number is proposed. The correlation is appl...

The effect of imperfectly conducting bounding plates on the heat transport in turbulent thermal convection in the Rayleigh-Bénard problem is considered in the context of analytical upper bounds. Beginning with the evolution equations in the fluid in the Boussinesq approximation, coupled through temperature and flux continuity to identical upper and lower conducting plates with diffusive heat fl...

In this paper a numerical investigation is performed to study the effects of different nanofluids on convective heat transfer enhancement in a partitioned square cavity subject to different shapes of nanoparticle using water-SiO2 nanofluid. This study has been carried out to analyze the effects of SiO2 nanoparticle, its volumetric fraction between 2 and 4%, and nanoparticle shape (i.e. blades, ...

The influence of linear, parabolic and inverted temperature gradients on the onset double-diffusive Rayleigh-Darcy convection is theoretically investigated. composite system constrained horizontally by adiabatic free-free thermal boundaries, appropriate interfacial boundary conditions are used to connect fluid-porous layers. regular perturbation approach determine critical Rayleigh number expre...

We present an experimental investigation of Rayleigh-Bénard convection in binary-gas mixtures. In order to interpret the results quantitatively, we determined the necessary thermodynamic and transport properties for six mixtures ~He-CO2, He-SF6, He-Xe, Ne-Ar, Ar-CO2, and H2-Xe! by a combination of data from the literature, molecular-theory calculations, and thermal-conductivity measurements. Al...