Plume Characterisation of a Single Source Electrospray for Micro Electronic Cooling

Abstract

Development and optimization of two phase electrospray cooling is an undeveloped topic, in part due to unavailable knowledge of how the various electrical, geometrical, thermal and hydraulic parameters influence both average and local heat transfer coefficients. Electrospray cooling (EC)enables two phase cooling by utilizing Coulomb forces for energy efficient fluid atomization while at the same time offering enhanced heat transfer using very small volumes of fluid. This research aims to characterize local heat transfer for different nozzle sizes (d), source to target separation heights (H), volumetric flow rates(Q), and target surface heat fluxes(q//). The results show that the peak heat transfer coefficient and the region of enhanced radial cooling are dependent on separation height and cooling fluid flow rate with minor dependency on nozzle size for certain cases. Importantly, the results show that very high peak heat transfer enhancement over natural convection can be achieved with electrosprays with exceptionally low flow rates.