Experimental investigation of a porous heat sink characterized by straight circular ducts

An experimental and theoretical investigation of convection heat transfer for a porous heat sink is performed. The porous heat sink is characterized by straight circular ducts uniformly arranged in an aluminum block. The diameter of each duct is 1.5 mm. The cooling fluid is water, with the flow rate ranging from 1.13 ml/s to 1.32×10² ml/s and the pore-scale Reynolds number Re from 8.50 to 9.82×10². The measured heat transfer coefficient based on the temperature difference between the wall to the inlet fluid is found ranging 0.21-1.64 W/cm², which is much higher than the results from packed-bead systems and comparable to the results from sintered copper-bead porous systems. In the theoretical analysis, the local thermal non-equilibrium is considered. The Nusselt numbers from the experiment and the theoretical prediction are compared and satisfactory agreement is found. Finally, a fitted correlation in terms of InRe for the measured Nusselt number is obtained