Experimental investigation of hydrodynamic performance of piranha pin fin micro heat sinks under adiabatic condition

Abstract

Piranha pin fin micro heat sink, a newly emerged cooling approach aiming at serving as a promising alternative to traditional heat sinks, has recently received considerable attentions. This study concerns the hydrodynamic performance of a two-phase heat sink containing an array of staggered piranha pin fins having various designed geometries under adiabatic condition. The working fluid was chosen to be HFE-7000. A test fixture having one inlet and multiple outlets and embedding a micro channel with 2.4 mm wide and 200 µm deep was fabricated serving for residing the micro devices on which piranha pin fin array was built. Four flow rates of 20, 30, 40, and 50 SCCM, and three different flow configurations including open flow, bypass only flow, and extraction only flow, were studied. Pressure drop and extraction ratio were experimentally obtained. Friction factor, f, and pressure loss coefficient, K, were numerically determined by using previously studied correlations based on experimental data. Plots characterizing the trends of friction factor, pressure loss coefficient, and pressure drop with respect to Reynolds number were gained. A correlation was developed to relate extraction ratio, f, and K. Comparisons between extraction ratio determined experimentally and calculated by newly developed correlation were also presented.