Hydrodynamics of Drop Impact and Spray Cooling through Nanofiber Mats

Spray cooling is one of the effective technologies has been promised for the thermal management of microelectronic systems and server rooms. The focus of this research is to increase the heat flux rate from a hot surface by applying a metal-coated electrospun polymer nanofiber mat. Samples were prepared from copper plate substrate coated with electrospun polymer nanofiber mat and electroplated with one of three different metals: nickel, copper and silver. Experiments were performed in which samples were subjected to impacting water droplets from a height of 17.95cm at various temperatures. The behaviors of droplet impact and subsequent evaporation were observed in order to evaluate and compare heat transfer characteristics of the different sample types. Silver-plated samples were found to provide the highest heat flux rate, followed by copper and then nickel. However, silver was not usable at higher temperatures due to its tendency to oxidize and degrade easily.