Experimental study of pressure drop and heat transfer in a single-phase micropin-fin heat sink

The pressure drop and heat transfer characteristics of a single-phase micropin-fin heat sink were investigated experimentally. Fabricated from 110 copper, the heat sink contained an array of 1950 staggered square micropin fins with 200 x 200 [micro][m.sup.2] cross section by 670 [micro]m height. The ratios of longitudinal pitch and transverse pitch to pin-fin equivalent diameter are equal to 2. De-ionized water was employed as the cooling liquid. A coolant inlet temperature of 25[degrees]C, and two heat flux levels, [q.sup.'.sub.eff]=50 W/[cm.sup.2] and [q.sup.'.sub.eff] = 100 W/ [cm.sup.2], defined relative to the platform area of the heat sink, were tested. The inlet Reynolds number ranged from 93 to 634 for [q.sup.'.sub.eff] =50 W/[cm.sup.2], and from 127 to 634 for [q.sup.'.sub.eff] = 100 W/[cm.sup.2]. The measured pressure drop and temperature distribution were used to evaluate average friction factor and local averaged heat transfer coefficient/ Nusselt number Predictions of the previous friction factor and heat transfer correlations that were developed for low Reynolds number (Re