honeycomb; rayleigh number; transparent insulation material
This article presents the mathematical theory of convective stability of a fluid (air) layer bounded by square honeycomb. The critical Rayleigh as well as post-critical Rayleigh regions are examined through the Nusselt number. The governing equations of square celled air temperature, vorticity, stream functions and velocity are solved by a finite difference method of explicit type, with central difference in space and foward difference in time, and the Nusselt number is calculated from known temperature and velocities. The effect of aspect ratio of cell, aspect ratio of wall and inclination of cell on suppression of convective motion are investigated. It is shown that the convective motion can be suppressed completely by varying the aspect ratio of the cell. In the post-critical Rayleigh region, thin walled honeycomb shows lower convective losses than thick walled devices.