Rayleigh-Bénard convection is the buoyancy-driven flow of a fluid heated from below and cooled from above. This model of thermal convection is a paradigm for pattern formation and turbulence [1] and it plays an important role in a large range of phenomena in geophysics, astrophysics, meteorology, oceanography and engineering. The problem under investigation is: given an incompressible fluid enc...

High resolution computer simulations of two-dimensional convection using the anelastic approximation are presented. These calculations span Rayleigh numbers from 10(8)-10(12) for Prandtl number equal to unity, with the fluid density decreasing by a factor of 12 from the bottom to the top of the convection region. This range covers several decades in the "hard" turbulent regime. While many studi...

2014 We have measured, in a Rayleigh-Benard experiment in liquid helium, the time dependent effects occurring above the onset of convection, using a local probe. Results are very dependent on the aspect ratio 0393, ratio of the cylinder cell radius to its height. For a small aspect ratio, 0393 = 2 and 0393 = 2.5, well defined sharp oscillations are present for a large range of Rayleigh numbers....

Convection of an internally heated fluid, confined between top and bottom plates of equal temperature, is studied by direct numerical simulation in two and three dimensions. The unstably stratified upper region drives convection that penetrates into the stably stratified lower region. The fraction of produced heat escaping across the bottom plate, which is one half without convection, initially...

in this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. the inner and outer cylinders are kept at constanttemperature ti and to respectively, where ti>to. the annular space is filled with alumina-water nanofluid.the governing equations with the corresponded boundary conditions in the polar coord...