Effect of dual flow arrangements on the performance of mini-channel heat sink: numerical study

Water-cooled heat sinks now gained the popularity due to increased heat generation inside the microprocessor. The generated high heat flux should be removed timely and uniformly for durability of microprocessor. In this work, the thermal performance of mini-channel heat sinks for fin spacing of 0.2 mm, 0.5 mm, 1 mm and 1.5 mm is numerically investigated with various dual flow arrangements. A uniform temperature distribution is observed for all dual flow arrangements discussed in this study which was not possible using single flow inlet/outlet. A direct influence of dual flow arrangements on base temperature and pressure drop of heat sink is evaluated. The results are then compared with the conventional single flow arrangement having same dimensioned heat sink available in the literature for water as well as for Al2O3-H2O nano-fluids. The maximum drop in base temperature was noted for rectangular inlet-circular outlet duct (no gap) flow arrangement as 14.3%, 15.4%, 16.06% and 15.6% for 0.2 mm, 0.5 mm, 1 mm and 1.5 mm fin spacing, respectively, as compared to the conventional single flow arrangement using water as a cooling fluid. Rectangular inlet-circular outlet duct (no gap) was found to be the best dual flow arrangement for all fin spacing investigated. The rectangular collector was then replaced by isosceles triangular collector for the best dual flow arrangement. The maximum reduction in net mass was noted as 12.0%, using isosceles triangular collector as compared to rectangular collector with same thermal performance. Dual rectangular inlet-circular outlet (no gap) flow arrangement highlights palpable improvement in hydrothermal performance compared to the conventional single circular inlet/outlet flow arrangement along with temperature uniformity.