Performance and Flow Characteristics of Miniature EHD Air Blowers for Thermal Management Applications

Electrohydrodynamic (EHD) air blowers are receiving increasing attention as a thermal management cooling solution to overcome the restrictions of traditional rotary cooling systems used in small-scale consumer electronics. In this work, the performance and flow pattern characteristics of miniature EHD air blowers are evaluated for practical convective heat transfer applications, based on device size, operating voltage and power, and generated flow rate. For a range of blower heights up to 10 mm, two-dimensional (2D) and three-dimensional (3D) numerical models of a wire-to-plane EHD channel configuration are developed and validated against previous experimental data. Investigation of the influence of blower sidewalls, based on width parameter, on flow characteristics reveals that the 2D simulations for short and wide blower domains are valid to predict the generated flow rates effectively compared to that obtained by the means of 3D simulations. An optimized combined EHD blower is developed as a flow-controlled cooling system in thermal management applications, which minimizes the required operating voltages for specified flow rates. Comparisons against commercial rotary blowers demonstrate that the miniature EHD blowers are more competitive as cooling solutions for compact applications and extended heated surfaces based on transduction efficiency, blower size, flow production of uniform velocity profile, and power consumption.