Chapter 1, Problem 1.54P

Convection ovens operate on the principle of inducing forced convection inside the oven chamber with a fan.A small cake is to be baked in an oven when the convection feature is disabled. For this situation, the freeconvection coefficient associated with the cake and its panis $h_{fr}=3{\text{W/m}}^{\text{2}}\cdot \text{K}$ . The oven air and wail are attemperatures $T_{\infty }=T_{sur}=180\text{°C}$ . Determine the heat flux delivered to the cake pan and cake batter whenthey are initially inserted into the oven and are at a temperature ot $T_i=24\text{°C}$ . If the convection feature is activated, tile forced convection heat transfer coefficientis $h_{\text{fo}}=27{\text{W/m}}^{\text{2}}\cdot \text{K}$ . What is the heat flux at the batter orpan surface when the oven is operated in the convectionmode? Assume a value of 0.97 for the emissivity of thecake hatter and pan.