Experimental investigation of the thermal and hydrodynamic characteristics of Y-shaped bifurcation flow channel heat sinks

The primary objective of this study is to conduct an empirical investigation into the heat transfer and fluid flow characteristics of heat sinks featuring Y-shaped bifurcation flow channels. Two 80-mm diameter dish-shaped heat sinks are fabricated by implementing constructal and fractal-like branching flow network designs. The ratio of the hydraulic diameter for the rectangular flow channel in the Y-shaped bifurcation can be expressed as D h,i+1 /D h,i = 2 −1/3 . The experiments utilize inlet water temperatures ranging from 20 to 35 °C, water flow rates between 0.013 and 0.033 kg/s, and input power levels between 0 and 500 W. The results show a nearly uniform surface temperature distribution with a maximum variation of ±1 °C. Increasing flow rates reduce thermal resistance by up to 18 % while increasing pumping power by approximately 12 %. At an inlet temperature of 20 °C, thermal resistance decreases by 15 % compared to 35 °C. A comparative analysis of the two designs reveals that the constructal heat sink requires 10 % less pumping power but exhibits 2.63 % higher thermal resistance than the fractal-like design. This suggests that heat sink designs should be based on application requirements to balance energy consumption and thermal dissipation efficiency for optimal performance. Our research also presents a comparison of Y-shaped bifurcation designs, supporting findings from simulation studies. The results confirm the consistency between experimental and numerical data, reinforcing the effectiveness of Y-shaped bifurcation structures in balancing thermal management and operational efficiency for advanced cooling applications.