Study on moving nozzle effects on spray cooling of electronics

Temperature rise of the electronic devices limits their efficiency, therefore, it is important to develop new methods to keep them in an operable temperature. In the current study, thermal performance of enhanced surfaces with different fin heights was investigated. The cooling process was carried out by spraying water out of moving and fixed nozzle, the nozzle movement along the rectangular heated surfaces was performed by a stepping motor. It was found that, flat surface showed better temperature uniformity than finned surfaces because of improved water evacuation. However, the temperature uniformity in the finned surfaces was improved with the nozzle movement. Furthermore, the surface with fins of 1 mm height showed higher heat transfer coefficient than the flat surface and the surface with fins of 3 mm height for all heat fluxes tested. At low heat flux, flat surface showed higher heat transfer coefficient than the surface with fins of 3 mm height because of formation of a water layer caused by the capillary action. Nevertheless, at high heat flux, the evaporation of water from the film on the surface, made the heat transfer coefficient of the surface with fins of 3 mm height larger than the flat surface.