Experimental Studies on the Enhanced Thermal Performance of Heat Sink Cooling With Pin‐Fin Orientation in Parallel Channels

The study presents a comprehensive experimental and numerical analysis into thermal and hydraulic characteristics of heat sink with parallel channel enhanced with symmetrical $$\text{NACA}$$ 0040 pin fins arranged in forward and backward orientations. $$\text{NACA}$$ pin fins are strategically placed in between the parallel channels to take the advantage of both plate and $$\text{NACA}$$ pin fins to intensify convective heat transfer while minimizing pressure drop. In the present study, the effect of forward and backward orientations of $$\text{NACA}$$ 0040 pin fins is investigated over Reynolds number $$(\text{Re})$$from 300 to 3300 by varying the relative streamwise pitch ( $${P}_{x}/{L}_{{hs}}$$) from 0.23 to 0.27 and the relative pin-fin thickness ( $$b/{S}_{f}$$) from 0.3 to 0.5, where $${P}_{x}$$ represents the streamwise pitch, $${L}_{{hs}}$$is the heat sink length, $$b$$ is the pin-fin thickness, and $${S}_{f}$$ is the fin spacing. Results reveal that the pin fins with forward orientation significantly improve the heat transfer while lowering pressure drop due to their streamlined shape and controlled vortex phenomenon. In contrast, the backward orientation causes more flow separation and recirculation, thereby reducing performance. Heat sink with forward orientation configuration achieves the highest thermohydraulic performance parameter (THPP) value of 1.71 at $${P}_{x}/{L}_{{hs}}=0.25$$ and $$b/{S}_{f}=0.4$$ demonstrating an optimal balance between enhanced heat transfer and the associated pressure drop penalty.