Natural convection heat transfer enhancement in new designs of plate fin based heat sinks
Abstract 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 x 106 to 9.5 x 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.