The thermal performance of pin-fin heat sinks with confined and submerged liquid water jet array impingement was investigated experimentally.The experimental results indicate that:the performance of heat sinks is closely related to the height of the pin-fin

but not the higher the better;Nusselt number is represented by pyramidal distribution in 0.625≤W/G≤1.000 ;for the confined and submerged jet arrays a strong dependence on both jet-to-target and jet-to-jet spacing can be observed

and Nusselt number falls continu ously between 2.5≤H/d≤10.0 ;an increment in jet-to-jet spacing between 3.00~4.50 can be found to decrease Nusselt number when Re<4000;a reduction in jet-to-jet spacing between 4.50~7.00 can be found to decrease Nusselt number rapidly

especially for high Reynolds number.The thermal resistance of heat sinks will decline with the increase of pump power

but then change slowly.