Natural convection heat transfer enhancement in new designs of plate-fin based heat sinks

• Published in: International journal of heat and mass transfer 2018-10, Vol.125, p.640-647
• Main Authors: Haghighi, S. Sadrabadi, Goshayeshi, H.R., Safaei, Mohammad Reza
• Format: Article
• Language: English
• Subjects: Convective heat transfer; Empirical equations; Fin spacing; Fluid flow; Free convection; Free convection heat transfer; Heat sinks; Heat transfer; Heat transfer coefficients; Plate cubic pin fin heat sink; Plate-fin heat exchangers; Rayleigh number; Thermal resistance
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2018.04.122

[Display omitted] •New designs of plate-fin and plate cubic pin–fin heat sinks were performed.•Free convection of airflow was measured over heat sinks experimentally.•Effects of fin shape, spacing and numbers, heat input and Ra have been studied.•Heat transfer enhancement of new-designed heat sinks is about 10% to 41.6%.•Increasing number of fins cause lower thermal resistance. Experimental investigation was conducted to measure the convective heat transfer coefficient and thermal performance of plate fins and plate cubic pin-fins heat sinks, under natural convection regime. The investigation was conducted for Rayleigh number from 8 × 106 to 9.5 × 106 and input heat of 10 W to 120 W. The fin spacing and fin numbers are varied between 5–12 mm and 5–9, respectively. The results demonstrated that plate cubic pin-fins heat sinks have lower thermal resistance and higher heat transfer, compared to plate fins heat sinks. Heat transfer enhancement of new-designed heat sinks is about 10–41.6% higher, compared to normal pin-fins. Increasing fin spaces in all types of studied heat sinks cause lower thermal resistance. But, increasing fin numbers does not cause better heat transfer. The best heat sink design was a plate cubic pin–fin heat sink with 7 fins and 8.5 mm fin spacing. Finally, empirical equations have been developed to correlate the average Nusselt number as a function of number of fin plates, fin spacing to height ratio as well as Rayleigh (and consequently Grashof) number.