Horizontally extended turbulent convection, termed mesoscale convection in natural systems, remains a challenge to investigate both experiments and simulations. This is particularly so for very low molecular Prandtl numbers, such as occur stellar the Earth's outer core. The present study reports three-dimensional direct numerical simulations of Rayleigh–Bénard square boxes side length $L$ heigh...

Bounds are derived for rotating Rayleigh–Bénard convection with free slip boundaries as a function of the Rayleigh, Taylor and Prandtl numbers ${\textit {Ra}}$ , {Ta}}$ {Pr}}$ . At infinite {Ta}} > 130$ Nusselt number {Nu}}$ obeys {Nu}} \leqslant \frac {7}{36} \left ({4}/{{\rm \pi} ^2} \right )^{1/3} {\textit {Ra}} {Ta}}^{-1/3}$ whereas kinetic energy density $E_{kin}$ $E_{kin} ({7}/{72 {\rm...

The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the surface wave solutions. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the frequency equation of Rayleigh wave. The numerical values of the non-dimensional speed of Rayleigh wave speed are computed for different values of frequency...

The geometrically different plan forms of near wall plume structure in turbulent natural convection, visualised by driving the convection using concentration differences across a membrane, are shown to have a common multifractal spectrum of singularities for Rayleigh numbers in the range 10 − 10 at Schmidt number of 602. The scaling is seen for a length scale range of 2 and is independent of th...

We report experiments on turbulent Rayleigh-Bénard convection of air in a cylindrical large-scale facility with a diameter of 7 meters and Rayleigh numbers up to Ra approximately 10(12). The facility is used to explore the structure of the large-scale circulation for continuously varying aspect ratios between Gamma approximately 1 and Gamma approximately 10. Using autocorrelation functions deri...

This paper represents the MIMO channel capacity over Rician fading, Rayleigh fading and Nakagami fading channel. Here Rician fading model employs a zero-mean stochastic sinusoid as the line-of-sight component. This paper offers analyses and simulations to the behavior of MIMO system and its expected capacity for various channel distribution under flat fading. Several types of distributions (Ric...

Isoscalar surfaces in turbulent flows are found to be more complex than (selfsimilar) fractals, in both the far field of liquid-phase turbulent jets and in a realization of Rayleigh-Taylor-instability flow. In particular, they exhibit a scaledependent coverage dimension, D2(λ), for 2-D slices of scalar level sets, that increases with scale, from unity, at small scales, to 2, at large scales. Fo...

Isoscalar surfaces in turbulent ows are found to be more complex than (selfsimilar) fractals, in both the far eld of liquid-phase turbulent jets and in a realization of Rayleigh-Taylor-instability ow. In particular, they exhibit a scaledependent coverage dimension, D2( ), for 2-D slices of scalar level sets, that increases with scale, from unity, at small scales, to 2, at large scales. For the ...

The problem of free convection flow and heat transfer of a fluid inside a square cavity having adiabatic obstacle positioned in the center of the cavity has been investigated numerically using a penalty finite element method. Calculations have been made for Rayleigh numbers ranging from 10 to 10 for an obstacle of aspect ratios AR=0, 0.4, 0.5, 0.6. Nusselt number results are presented for Prand...