Natural convection from rectangular interrupted fins

• Natural convection from interrupted finned heatsinks is investigated in this study.
• Compact relations for optimum interruption length are introduced.
• The correlation is validated by results of an independent numerical model.
• An experimental study is conducted to verify the numerical results.

Steady-state external natural convection heat transfer from vertically-mounted rectangular interrupted fins is investigated numerically and experimentally. FLUENT software is used to develop a 2-D numerical model for investigation of fin interruption effects. A custom-designed testbed was developed and 12 different aluminum alloy heatsinks with various geometric dimensions are machined and tested to verify the theoretical results. A comprehensive experimental–numerical parametric study is performed to investigate the effects of fin spacing, and fin interruption. Our results show that adding interruptions to vertically-mounted rectangular fins can enhance the thermal performance considerably and that an optimum fin interruption exists. A new compact correlation is proposed for calculating the optimum interruption length. The results of this work can be used to improve natural heat transfer from enclosures in a variety of electronics, power electronics and telecom applications.