Case 1: From Fig. 4.2(b), it is observed that the upper part of cavity remains nearly isothermal due to the air flow from inlet whereas the rest of the cavity thermally stratified. A recirculation zone (Fig. 4.2(a)) appears just below the upper stream. Non-dimensional horizontal velocity and temperature distributions are shown in Fig. 4.3(a) and 4.3(b). It is observed that when the flow velocity increases, the isothermal region also increases.

Case 2: A weak recirculation region(Fig. 4.4(a)) is found compared to the case 1 due to the lower inlet velocity. The isothermal region(Fig. 4.4(b)) also decreases. From the Table 4.1, it can be seen that, heat transfer is enhanced by increasing the velocity. The Nusselt number along the cold wall increases, when the inlet velocity increases. This indicates that the heat transfer by forced convection is more effective than the free convection.