Influence of surfactant on friction pressure drop in a manifold microchannel

Manifold microchannel (MMC) heat sinks have many advantages on low thermal resistance, compact structure, small amount of coolant, low flow rate, uniform temperature distribution along the flow direction, etc. However, a high pressure drop is needed due to the small channel size used thus the pumping power is increased. Here we study the effect of surfactant on friction pressure drop in a specifically designed manifold microchannel heat sink. The microchannel has a cross section of 100 microns by 300 microns with a length of 10.0 mm. An anionic surfactant of 100 ppm Sodium Dodecyl Sulphate (SDS with 95% purity grade) aqueous solution and a new type of 300 ppm green non-ionic surfactant of Alkyl Polyglycoside (APG1214 with 98% purity grade) aqueous solution are used as the working fluids. It is found that the drag reductions are dependent on the flow velocities and the fluid temperatures. The drag reduction is not significant for laminar flow, but it is increased in the transition flow regime. The temperature rise can promote the drag reductions in the presence of SDS and APG. It is shown that the APG is better than the SDS regarding the drag reductions at high temperatures.