Natural convection in circular enclosures heated from below for various central angles

Two-dimensional numerical simulations have been performed to study natural convection in circular enclosures filled with water considering different central angles. Continuity, momentum and energy equations are solved assuming Boussinesq approximation utilizing COMSOL. Effect of Rayleigh number, Ra, on heat transfer rate is investigated by showing Nusselt number, Nu, for a range from 1×103 to 1×107. It is shown that decreasing central angle of the cavity increases averaged Nusselt number in a cavity heated from below. Finally, a correlation for heat transfer rate is developed considering the effect of the angle between two sides of the cavity and Ra number using simulation results.