Answer:
0.08704 W
Explanation:
converting the mm to m (1000mm = 1m)
cross-sectional area of the fins, Ac = (0.003) (0.0004) = 0.0000012m^2
The wetted perimeter of the cross-section, P = 2 (0.003 + 0.0004) = 0.0068m
Thickness of solid in direction of heat flow, B^2 = (heat transient coefficient, h) (The wetted perimeter of the cross-section, P) ÷ (Thermal conductivity, k) (cross-sectional area of the fins, Ac)
B^2 = (8 W/m2K)(0.0068m) ÷ (175 W/mK)(0.0000012m^2)
=259.0476m^-2
B= square root of the result
B = 16.09m^-1
we now look for:
The Coordinate, x = B, multiplied by Length, L
x = (16.09m^-1) (0.04m) = 0.6436
finding the side area of a fin = P multiplied by Length, L
= 0.0068m X 0.04m = 0.000272m^2
Neglecting inefficiency, assuming the fins are all 100% efficient, the power they would dissipate =
h, Heat-transfer coefficient (PL) (temperature of at the base - temperature at the ambient air)
= (8) (0.000272m^2)(340 K- 300k)
= 0.08704 W
