Effect of Fin Geometry on Heat Dissipation from Extended Surfaces: An Experimental and Comparative Study

Extended surfaces, commonly called fins, are used across the engineering world to enhance heat transfer from hot surfaces to surrounding fluids. Their effectiveness depends on the geometry, material, and airflow conditions. This experimental study compares four fin geometries — rectangular, triangular, pin, and annular — fabricated from aluminium alloy Al 6061 and attached to a base plate maintained at a uniform temperature using an electric heater. Under controlled natural convection conditions, temperature distributions along the fin length, heat dissipation rates, and fin efficiency were measured and compared at three base temperatures (60°C, 80°C, 100°C). Rectangular fins showed the highest heat dissipation rate of 28.4 W at 100°C base temperature, while annular fins achieved the highest fin efficiency of 0.82. Triangular fins offered the best performance-to-weight ratio. Pin fins showed the most uniform temperature distribution. These quantitative comparisons provide useful guidance for selecting fin geometry in electronic cooling, heat exchanger, and engine cooling applications.