ABSTRACT
In this chapter, numerical simulation is carried out to study the natural convection flows in a north-light roof under winterday boundary conditions. The winterday boundary conditions such as hot bottom wall due to room heating and cold ceiling due to environmental temperature are adopted for the present study. The steady-state solutions have been obtained for a Rayleigh number ranging from 103 to 106 and Pr = 0.7. In this chapter, natural convection heat transfer in a traditional north-light roof is quantitatively investigated through isotherm pattern, streamline pattern, local and average Nusselt number. The results indicate that magnitude of the stream function is low at lower Rayleigh number due to conduction domination. However, it increases with an increase in Rayleigh number due to the transition from conduction dominant to convection dominated mode. It is observed that the rate of heat transfer is found to be minimum at the center of the bottom wall. It increases further at a greater rate in the right-hand side of the roof than left. This is because of large cooling area at the right side. It is noticed that as the Rayleigh number increases, multiple-cell solution is developed between hot bottom and cold inclined walls.
