Discuss the below:
Q: A 0.3-cm thick aluminum plate has rectangular fins on one side, 0.16 A=0.6 cm, spaced 0.6 cm apart. The finned side is in contact with low pressure air at 38°C and the average heat transfer coefficient is 28.4 W/(m2 K). On the unfinned side water flows at 93°C and the heat transfer coefficient is 283.7 W/(m2 K).
(a) Calculate the efficiency of the fins
(b) Calculate the rate of heat transfer per unit area of wall and
(c) comment on the design if the water and air were interchanged.
GIVEN
Aluminum plate with rectangular fins on one side
Plate thickness (D) = 0.3 cm = 0.003 m
Fin dimensions (t A? L) = 0.0016 m A? 0.006 m
Fin spacing (s) = 0.006 m apart
Finned side
Air temperature (Ta) = 38°C
Heat transfer coefficient ( ha ) = 28.4 W/(m2 K)
Unfinned side
Water temperature (Tw) = 93°C
Heat transfer coefficient ( hw ) = 283.7 W/(m2 K)
ASSUMPTIONS
The aluminum is pure
Width of fins is much longer than their thickness
The system has reached steady state
The thermal conductivity of the aluminum isconstant
