Natural convection of air in a square cavity: A bench mark numerical solution

Abstract Details are given of the computational method used to obtain an accurate solution of the equations describing two‐dimensional natural convection in a square cavity with differentially heated side walls. Second‐order, central difference approximations were used. Mesh refnement and extrapolation led to solutions for 10 3 ⩽Ra⩽10 6 which are believed to be accurate to better than 1 per cent at the highest Rayleigh number and down to one‐tenth of that at the lowest value.