Heat exchanger design: Optimal uniform separation between rectangular fins protruding from a vertical rectangular base

Steady-state rates of heat loss, from an array of 3 mm thick, 250 mm long, horizontal rectangular duralumin fins extending 60 mm perpendicularly out of a 250 mm x 190 mm vertical rectangular duralumin base, have been measured. With the base, at a uniform temperature of between 40°C and 80°C, in a 20°C ambient environment, two separations of the parallel fins, corresponding to maxima in the rate of heat loss versus fin separation curves ensued, respectively at 12 ± 1 mm and 38 ± 1 mm. The use of the latter maxima (i.e. the optimal separation) leads to the higher rate of heat loss. The heat transfer performances of vertical and horizontal rectangular fin arrays on a vertical rectangular base are compared: using the same geometrical configuration and identical base temperatures in both cases, the vertical fin orientation has the more rapid, steady-state heat loss.