A first incursion into the 3D structure of natural convection of air in a differentially heated cubic cavity, from accurate numerical solutions

摘要

Accurate solutions to the equations governing the natural convection of air in a cubic cavity, thermally driven on two vertically opposite faces, are given for Rayleigh number values up to l0~7. These solutions are obtained with a pseudo-spectral Chebyshev algorithm based on the projection diffusion method [l,2] with a spatial resolution supplied by polynomial expansions, which go up to lllxlllxlll. The solutions are believed to be accurate- better than (0.03, 0.05)/100 in relative global error for the corresponding Rayleigh number (Ra) range (l0~3, l0~7). This clearly indicates a non monotonic evolution of the flow structure as Ra increases.