摘要： It is crucial to control the temperature of solar cells for enhancing e?ciency with the increasing power intensity of multiple photovoltaic systems. In order to improve the heat transfer e?ciency, a microchannel heat sink (MCHS) with V-ribs using a water-based nano?uid as a coolant for micro solar cells was designed. Numerical simulations were carried out to investigate the ?ows and heat transfers in the MCHS when the Reynolds number ranges from 200 to 1000. The numerical results showed that the periodically arranged V-ribs can interrupt the thermal boundary, induce chaotic convection, increase heat transfer area, and subsequently improve the heat transfer performance of a MCHS. In addition, the preferential values of the geometric parameters of V-ribs and the physical parameters of the nano?uid were obtained on the basis of the Nusselt numbers at identical pump power. For MCHS with V-ribs on both the top and bottom wall, preferential values of V-rib are rib width d/W = 1, ?are angle α = 75°, rib height hr/H = 0.3, and ratio of two slant sides b/a = 0.75, respectively. This can provide sound foundations for the design of a MCHS in micro solar cells.