Wicking Nanofence-Activated Boundary Layer to Enhance Two-Phase Transport in Microchannels

Controlling the movement of liquids/vapors on solid interfaces is of importance for numerous applications ranging from fluid processing to lab-on-chip and thermal management systems. In this study, a new mechanism is proposed to coordinate the two-phase transport during a boiling process in a highly on-demand fashion. A novel wicking nanofence was designed to confine liquids as an ordered, reconfigurable boundary layer that allows for significant enhancements in all aspects of two-phase transport performances. Experiments have been conducted to systematically investigate the effect of a nanofence-activated boundary layer on the flow boiling performance for mass velocity ranging from 113 to 389 kg/m²·s. Significant enhancements regarding the heat transfer coefficient (HTC) and critical heat flux (CHF) have been demonstrated. For example, a CHF value of 585 W/cm² with an enhancement of about threefold is achieved compared to a plain-wall microchannel at a mass velocity of 389 kg/m²·s. The HTC enhancement is up to 58% as well at a mass velocity of 160 kg/m²·s. All these achievements are demonstrated without escalating the pressure drops.