ONSET OF NATURAL-CONVECTION IN A CUBE

The problem of transient natural convection in a cube-shaped cavity is investigated experimentally and numerically. The motion is driven by a sudden temperature difference applied to two opposite side walls of the vessel. The experiments are performed at a Rayleigh number of 1.66 x 10(5) and a Prandtl number of 1109, inside a 5 x 5 x 5 cm3 cavity m ade of Plexiglas, with two isothermal copper walls kept at a prescribe d temperature. Numerical simulation has been performed using a finite difference vorticity velocity model of the Navier-Stokes equation with the Boussinesq approximation. The theoretical predictions are found t o be in good agreement with the experimental results.