Employing thin planar electrodes to expand the ionic wind flow coverage area and achieve enhanced heat dissipation

Abstract

The suboptimal photoelectric conversion efficiency of light-emitting diodes (LEDs) leads to increased temperature. There is a growing interest in using micro-structure ionic wind pumps to regulate the chip temperature. But the ionic wind flow and thermal transfer characteristics of thin-plate electrode pumps used for cooling LED chips is unclear. This study proposes ionic wind pumps equipped with wedged and zigzag-emitters to effectively manage the heat generated by high-power LED chips. Experimental investigations were conducted to analyze the electrohydrodynamic characteristics of pumps with different emitter types. A two-dimensional model with a wedged-electrode and a three-dimensional model with a zigzag-electrode were developed for flow distribution analysis and energy efficiency comparison. The cooling capacity of pumps with different configurations was examined. The results show that the pump equipped with a zigzag-electrode exhibits improved stability in corona discharge and approximately 1.53 times higher energy efficiency compared to the pump with a wedged-electrode. Moreover, the pump with the zigzag-electrode covers a larger area, generating a higher intensity of ionic wind. The angle between the emitter and the ground electrode significantly affects the characteristics of the characteristics of the ionic wind flow. The optimal angle is 70° for pumps with wedged-emitters and 30° for those with zigzag emitters. Both pumps can produce a steady wall jet at their optimal angle, causing significant disruption in the surrounding area. The pump with zigzag-electrode exhibits superior cooling performance and is more effective with low power consumption.