A cylindrical aluminum fin has a 1cm diameter and is 30 cm in length. It is attached to a surface at 80 and is exposed to the air at 220. The thermal conductivity is 237 W/m*k and the heat transfer coefficient is 18 W/m*k. Assume the fin to be very long. What is the rate of heat transfer from the fin effectiveness?

Q = 42.877

e = 76.87 %

Explanation:

Given:

- The diameter of the Aluminium rod d = 1 cm

- The Length of the Aluminium rod L = 30 cm

- The base Temperature of rod Tb = 80°C

- The temperature of ambient air T∞ = 220°C

- The thermal conductivity of rod k = 237 W/mK

- heat transfer coefficient is h = 18 W/m*k

Find:

What is the rate of heat transfer from the fin

What is the fin effectiveness?

Solution:

- The perimeter P of the fin:

                  P = pi*d

                  P = pi*0.01 = 0.03141 m

- The area of rod cross section A:

                  A = pi*d^2 / 4 = pi*0.01^2 / 4

                  A = 0.00007 m^2

- The heat transfer rate of fin:

Then:

- The effectiveness e of an infinitely long pin is as follows:

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