Symmetric and asymmetric trapezoidal fins with variable top surface slopes are investigated using a two-dimensional analytic method.  Shapes of symmetric and asymmetric fins are changed from rectangular through trapezoidal to triangular by adjusting the fin shape factor. The ratio of the heat loss from a symmetric trapezoidal fin to that from an asymmetric trapezoidal fin is examined as a function of the fin length, base height, and shape factor as well as the convection characteristic number. One of the results shows that heat loss from an asymmetric trapezoidal fin is larger than that from a symmetric trapezoidal fin, since the surface area of an asymmetric trapezoidal fin is larger than that of a symmetric trapezoidal fin, even though the fin volumes are the same.

symmetric trapezoidal fin, asymmetric trapezoidal fin, heat loss, convection characteristic number, fin shape factor.