Experimental determination of cooling and spray characteristics of the water electrospray

摘要

Over the last two decades, the dimensions of electromechanical systems have decreased to micro, even nano scale, as well as the capacity of these systems has increased, leading to the gradual increase of heat flux density. Hence, the conventional cooling methods cannot completely remove heat from the surface. Electrospray cooling is a novel method used in high heat flux systems with small surface area. In literature, studies investigating the relationship between electrospray cooling and spray characteristics are limited. In the present work, electrospray and cooling characteristics were determined for 3different nozzle diameters, 2 different nozzle - plate separation distances, 4 voltages and 3volumetric flow rates. The relationship between mean flow velocity, mean particle diameter and electrospray modes also were determined by digital image processing. The cooling enhancement ratio (CER) values were calculated for varying voltages, mean flow velocities and mean particle diameters. As a result, it was observed that with the increased voltage, the CER and mean flow velocity increased and the mean particle diameter decreased. According to the experimental results, the maximum value of CER was determined to be 1.9, where the mean velocity of the deionised water and the mean particle diameter were 9 m/s and 102 μm, respectively.