EXAMPLE 3-6 Heat Flux Boundary Condition Consider an aluminum pan used to cook beef stew on top of an electric range. The bottom section of the pan is L=0.3cm thick and has a diameter of D=20cm. The electric heating unit on the range top consumes 800W of power during cooking, and 90% of the heat generated in the heating element is transferred to the pan. During steady operation, the temperature of the inner surface of the pan is measured to be 110C. Express the boundary conditions for the bottom section of the pan during this cooking process. EXAMPLE 2-3 Heat Conduction through the Bottom of a Pan Consider a steel pan placed on top of an electric range to cook spaghetti (Fig, 3-15). The bottom section of the pan is L=0.4cm thick and has a diameter of D=18cm. The electric heating unit on the range top consumes 800W of power during cooking, and 80 percent of the heat generated in the heating element is transferred uniformly to the pan. Assuming constamt thermal conductivity, obtain the differential equation that describes the variation of the temperature in the bottom section of the pan during steady operation