Plant-Mimetic Heat Pipes for Operation with Large Inertial and Gravitation Stresses

Heat pipes and loop heat pipes have long been recognized as attractive alternatives to conventional heat exchangers, but the limit in the magnitude of the capillary pressures generated by the wicks in conventional designs has placed a severe limit on their applicability in vehicles and other large-scale applications. In this project, we aim to overcome this limitation by designing heat pipes with nano-porous wicks that support 10s of bars of capillary pressure. To this end, we are developing design concepts for heat pipes operating in this new regime, developing new fabrication strategies for hierarchically structured wicks that maximize capillary pressures while maintaining reasonable hydraulic resistances, and elucidating the strategies exploited by vascular plants to manage large capillary pressures and the associate metastability of the liquid phase.
The original document contains color images. Prepared in cooperation with Harvard University.