Abstract
The present study proposes an estimation model for free convection heat transfer in a stably stratified layer, where a lot of free convection cells are formed and each cell contributes the total heat transfer. Since the over-all heat transfer coefficient can be estimated by the heat transfer coefficient of each small cell, the present study developed a correlation formula of free convection heat transfer coefficient in an enclosed chamber. The heat transfer coefficient was numerically analyzed for free convection in a rectangular cavity and the correlation formula was developed over a wide range of the aspect ratio Ar=0.1-20 and Rayleigh number Ra=10^3-10^7.
