Characterization of dynamics and heat transfer in electro-spray at elevated flow rates

The advancement of semiconductor and microelectronics technologies has underscored the increasing importance of efficient heat management in electronic devices. To overcome the shortcoming of low flow rates of electro-spray, the present study is motivated by using visualization and heat transfer performance experiments to reveal the morphology evolution and heat transfer characteristics of electro-sprays with high flow rates. The results indicate that the morphology of electro-sprays is closely related to the electric field intensity and the flow rate, and can be classified into six modes: dripping mode, spindle mode, cone jet mode, multi-cone jet mode, simple jet mode, and oscillating jet mode. Furthermore, the formation mechanisms and transition rules of these modes are discussed in detail. In addition, the effects of the flow rate, voltage, and spray morphology on the heat transfer performance of electro-sprays was investigated, and strategies for enhancing heat transfer were subsequently proposes. At a flow rate is 800 ml/h and an applied voltage is 6 KV, the critical heat flux (CHF) can reach 100.8 W/cm2, and the maximum heat transfer coefficient (hmax) can reach 14416.55 W/m2K. This study not only enhances the comprehension of high flow rate electro-spray technology, but serves as a vital reference for the design and application of electro-spray cooling devices.