EFFECTS OF VARIATION IN ROOT TEMPERATURE ON HEAT LOST FROM A THERMALLY NONSYMMETRICAL FIN

A discussion of the variation of the heat lost from a fin is presented the root temperature of which is T = T(w) + a cos(m) (pi-y'/2l), 0 less-than-or-equal-to m less-than-or-equal-to 5, and surface convection coefficients of which are constant but unequal. The range of parameters are 0 less-than-or-equal-to B2 less-than-or-equal-to B1 less-than-or-equal-to 1, B1 = 0.01, 0.1, 1.0 where B1 and B2 are the Biot numbers of the top and bottom surfaces, respectively. A fin justification criterion (fin heat loss greater than or equal to three times the no-fin heat loss) is used to discuss fin effectiveness. The results are (1) the heat lost from the fin decreases as m increases, a > 0; (2) tip Biot number is not an important factor in heat lost for large B1 and B2 and (3) as a increases (m constant) the heat lost increases almost linearly.