Numerical calculation of the heat transfer by natural convection in a cubical enclosure

Numerical calculations of the heat transfer by natural convection in a cubical box are described. Two vertical opposing walls are supposed isothermal. All sidewalls are assumed to be adiabatic or perfectly conducting. The Rayleigh range considered varied between 10,000 and 1,000,000. Air was taken as the working fluid and the flow was considered to be three-dimensional, laminar and stationary. Solutions of the governing equations are obtained with a method of finite differences using a nonlinear grid. A method is used to correct the results for the influence of the grid used in the numerical calculation by varying the nonlinearity parameter. Application of this more accurate method showed the value of the calculated Nusselt number to be smaller than the value obtained without the correction for the grid.