Hot air at 80°c is blown over a 2-m by> on0 4-m flat surface at 30°c. if the average? convection heat transfer coefficient varies between 20 w/m2 °c and 100 w/m °c, draw a relation between the rate of heat transfer from the air to the 80°c air 30°c plate.(nm kw) and the convection heat transfer coefficient

Explanation:

The given data is as follows.

       ,      

Area of the flat plate is 2 × 4 = 8 .

Average convection heat transfer coefficient = = .

Hence, formula to calculate heat transfer through convection from air to the water is given as follows.

                    q =

                        =

                        = 24000 W

or,                     = 24 kW

Hence, the direction of heat flow is from air to the surface.

Thus, we can conclude that transfer of heat is 24 kW.