Laminar Natural Convection Heat Transfer in a Horizontal Cavity with Different End Temperatures

The heat transfer by free convection in a horizontal cavity with adiabatic horizontal walls and differentially heated end walls is studied analytically. The paper develops three models for explaining and predicting the heat transfer mechanism in a cavity with the height/length aspect ratio considerably smaller than one. The three models are: 1) the regime of vanishing Rayleigh numbers, 2) the intermediate regime, and 3) the boundary layer regime. The transition from one model to the next occurs as the Rayleigh number increases. The Nusselt number prediction based on the three-regime theory agrees very well with available numerical and experimental heat transfer data.