A cooking oven has a top surface temperature of 45°C when exposed to still air. At this condition the inside oven temperature and room air temperature are 180°C and 20°C, respectively, and heat is transferred from the top surface at 40 W.
To reduce the surface temperature, as required by safety regulations, room air is blown across the top with a velocity of 20 m/s. Conditions inside the oven may be considered unchanged.
a. What will be the rate of heat loss under this new operating condition?
b. What will be the top surface temperature?