Abstract
Abstract
This work involves a numerical two-dimensional study on the effect of the
variation in heat transfer coefficient on the performance of annular fins. The
object was to study the effect of varying the heat transfer coefficient on the fin
efficiency. , Fin effectiveness, optimum length and the heat flow for fins of
different cross-section, namely, constant thickness, and trapezoidal assuming a
two dimensional flow inside the fin (radial and axial).
The results were obtained through setting up the governing equations and
solving them by a finite difference technique employing the method of grid
generation and coordinate transformation with the aid of the Gauss-Siedel
method.
A power relationship was used to describe the variation of the heat transfer
coefficient as a function of the fin length.
It was found that the variation in heat transfer coefficient reduces the fin
efficiency, effectiveness, optimum length and the temperature gradient at the root
of the fin and consequently the amount of heat transfer. Further more this
variation led to an increase in the volume required to dissipate a known quantity
of heat as compared to the constant coefficient case It was also found that heat
dissipation increased with the increase in fin length to a certain limit and then
begins to drop.
