LAUSR

Abstract In this study, splayed effects on the thermal performance of standard cross-cut heat sink (S–CCHS), fixed-array splayed (FAS-CCHS), and full splayed (FS–CCHS) under natural and forced conditions are studied experimentally and numerically. For this purpose, variable parameters such as splayed ratio, different powers of LEDs, natural and forced conditions, and blowing direction have been studied. The results showed that the thermal performance is significantly impacted by the spread position of the fins, blowing direction, natural and forced conditions of the CCHS but is not very sensitive to LEDs' powers. The results show that the full splayed heat sink occupies the highest physical volume, thus, provides the highest thermal performance by efficiently dissipating heat compared to other heat sinks designs. Experimental and numerical results show that the full splayed effect provides 5.46% and 2.59% lower junction temperature in natural and forced, respectively. Also, FS-CCHS achieved a 7.09% reduction in thermal resistance at natural convection 3 W and a 2.62% reduction at 10 W, respectively, compared to the flat fins and the fixed array wide fin heat sink. For this study, while the most suitable flow direction was determined as push, the most suitable orientation was found to be upward, and the splayed impact was also beneficial.