Water at 43.3°C flows over a large square plate at a velocity of 28 cm/s. The plate is 1.2 m long (in the flow direction) and its surface is maintained at a uniform temperature of 10.0°C. The width of the plate is 1.2 m. Calculate the steady rate of heat transfer for the entire width of the plate in watts (W). The properties of water at the film temperature of (Ts + T∞)/2 = (10 + 43.3)/2 = 27°C are ρ = 996.6  kg/m3, k = 0.610 W/m·°C, μ = 0.854 × 10–3 kg/m·s, and Pr = 5.85.

Heat transfer

2. Consider airflow over a plate surface maintained at a temperature of 215°C. The temperature profile of the airflow is given as T(y) = Too (Too - T,) exp (- V fluid The airflow at 1 atm has a free stream velocity and temperature of 5 cm/s and 25°C, respectively. Determine the heat flux on the plate surface and the convection heat transfer coefficient of the airflow.

Solar radiation is incident on the glass cover of a solar collector at a rate of 700W/m². The glass of collector absorbs 88 percent of the incident radiation on it and has an emissivity of 0.9. The entire hot water needs of a family can be provided by a single collector of 1.2m height and 2m width. The temperature of the glass cover of the collector is measured to be 35C° on a day when the surrounding air temperature is 25C° and the wind is blowing at 30km/h. The effective sky temperature for radiation exchange between the glass cover and the open sky is -40C°. Water enters the tubes which attached to the absorber plate at a rate of 1kg/min. Assuming the back surface of the absorber plate to be heavily insulated and the only heat loss to occur through the glass cover, determine (a) the total rate of heat loss from the collector, (b) the collector efficiency, which is the ratio of the amount of heat transferred to the water to the solar energy incident on the collector, and (c) the…

What are the differences between velocity boundary layer and thermal boundary layer? Discuss about both boundary layers including the characteristics, the profiles and factors affecting the boundary layers.