INSTABILITY OF THE RAYLEIGH-BENARD CONVECTION FOR INCLINED LOWER WALL WITH TEMPERATURE VARIATION

Investigation on Instability of Rayleigh-Benard Convection Using Lattice Boltzmann Method with a Modified Boundary Condition

In this study, the effects of Prandtl number on the primary and secondary instability of the Rayleigh-Benard convection problem has been investigated using the lattice Boltzmann method. Two different cases as Pr=5.8 and 0.7 representing the fluid in liquid and gas conditions are examined. A body forces scheme of the lattice Boltzmann method was presented. Two types of boundary conditions in the...

Unsteady Heating of Rayleigh-Benard Convection

The linear thermal instability of a horizontal fluid layer with time-periodic temperature distribution is studied with the help of the Floquet theory. The time-dependent part of the temperature has been expressed in Fourier series. Disturbances are assumed to be infinitesimal. Only even solutions are considered. Numerical results for the critical Rayleigh number are obtained at various Prandtl ...

Thermal Modulation of Rayleigh-Benard Convection

Thermal convection in a fluid layer confined between two horizontal rigid boundaries has been studied with the help of the Floquet theory. The temperature distribution consists of a steady part and an oscillatory time-dependent part. Disturbances are assumed to be infinitesimal. Numerical results for the critical Rayleigh numbers and wave numbers are obtained. It is found that the disturbances ...

Pretransitional Effects in the Rayleigh-benard Instability

Heat transport in turbulent rayleigh-Benard convection

We present measurements of the Nusselt number N as a function of the Rayleigh number R in cylindrical cells with aspect ratios 0. 5</=gamma identical withD/d</=12.8 ( D is the diameter and d is the height). We used acetone with a Prandtl number sigma = 4.0 for 10(5) less, similarR less, similar4x10(10). A fit of a power law N = N(0)R(gamma(eff)) over limited ranges of R yielded values of gamma(...