Question

Describe the differences, if any, between fin efficiency and fin resistance.

Answer 1

Answer:

$\eta =\dfrac{1}{mL}$

$R=\sqrt {\dfrac{KA}{hP}}$

Explanation:

Fin efficiency:

 Fin efficiency is the ratio of actual heat transfer through fin to the maximum heat transfer through fin.

For infinite long fin:

 Actual heat transfer

$q=\sqrt{hPKA}\Delta$

So the efficiency of fin

$\eta =\dfrac{1}{mL}$

Where

$m =\sqrt{\dfrac{hP}{KA}}$

h is heat transfer coefficient,P is the perimeter,K is the thermal conductivity and A is the cross sectional area.

$q=\sqrt{hPKA}\Delta$\

From equation we can say that fin resistance

$R=\sqrt {\dfrac{KA}{hP}}$

Thermal resistance offer resistance to flow of heat.