Multi-scale experimental and computational assessment of heat transfer behavior in compact short fin structures

The present study presents a comparative analysis of temperature distribution and heat transfer performance of short fins using experimental, simulation and theoretical method. An experimental setup was developed to investigate square, circular, rectangular, trapezoidal, and triangular fins under a constant heat input of 30 W, with specimen lengths of 0–80 mm, temperatures of 77–50 °C, and natural convection conditions (ambient air at 25 °C, velocity 0.2 to 0.5 m/s). Results show that square fins achieved the highest heat transfer rate (5.32 W), efficiency (94.86%), and effectiveness (23.77), while cylindrical fins performed slightly lower. Among materials, mild steel with a rectangular cross-section demonstrated superior thermal performance, with a heat transfer rate of 5.42 W and fin effectiveness of 25.89. Thermal resistances for mild steel, stainless steel, cast iron, and titanium were 10.61, 32.55, 18.21, and 42.83 °C/W, respectively. The study reveals how short-fin geometry and material influence heat transfer, airflow, and turbulence under natural convection. The findings are scalable, providing guidance for designing heat sinks and cooling systems. By integrating experiments and simulations, the research identifies optimal fin configurations and uncovers localized thermal and flow behaviors, offering practical strategies for improved thermal management.