Numerical Performance Characterization of an Innovative Micro-Scale Electrohydrodynamic Conduction Pumping Device

As technological advances lead to miniaturization of high power electronics, the concentration of heat generating components per area increases to the point of requiring innovative, integrated cooling solutions to maintain operational temperatures. Traditional coolant pumps have many moving parts, making them susceptible to mechanical failure and requiring periodic maintenance. Such devices are too complex to be miniaturized and embedded in small scale systems. Electrohydrodynamic (EHD) conduction pumps offer an alternative way of generating fluid flow in small scales for use in modern thermal control systems for high power electronics, both for terrestrial and aerospace applications. In EHD conduction, the interaction between an applied electrical field and the dissociation of electrolyte species in a dielectric fluid generates an accumulation of space charge near the electrodes, known as heterocharge layers. These layers apply electric body forces in the fluid, resulting in a flow in the desired direction based on the pump characteristics. EHD conduction pumps work with dielectric fluids and have simple, flexible designs with no moving parts. These pumps have very low power consumption, operate reliably for longer periods than mechanical pumps, and have the ability to operate in microgravity. EHD conduction pumps have been previously proven effective for heat transfer enhancement in multiple size scales, but were only studied in a flush ring or flush flat electrode configurations at the micro-scale. This study provides the pressure and flow rate generation performance characterization for a micro-scale pump with perforated electrodes, designed to be manufactured and assembled using innovative techniques, and incorporated into an evaporator embedded in an electronic cooling system. The performance of the pump is numerically simulated based on the fully coupled equations of the EHD conduction model, showcasing the distinctive heterocharge layer structure and subsequent force generation unique to this innovative design.