An Investigation of Optimum Spacing of Fins for Maximum Heat Loss in Free Convection

In designing a heat exchanger, an engineer is interested in the highest possible efficiency of the unit. If he is designing a transistor with an internal heat source, he is interested in dissipating this heat energy to the surrounding air or heat sink. In these and other devices, the engineer wants a design that gives a maximum heat loss, or heat transfer, per unit of base surface. The heat transfer coefficient of a heated object can be increased by extending its surface, thereby providing more surface area for heat transfer. If the maximum heat loss per unit area of base surface can be increased by extended surface, then fins placed on close center would be ideal. However, as the fins are placed closer and closer together, the finned tube approaches a thick circular cylinder with no advantage of extended surface. As the spacing of the fins would decrease, the heat lost would increase to a maximum and then decrease. The project reported in this thesis involved setting up the apparatus and determining experimentally, the optimum spacing for maximum free convection heat loss from parallel circular disks