Theoretically revisiting structural thermal armor for efficient Leidenfrost effect inhabitation

Abstract

Inhibiting Leidenfrost effect to enhance heat transfer is crucial yet a formidable challenge, particularly at extremely high temperatures. Previously, we developed a heterogeneous structural thermal armor (STA) that fundamentally inhibits Leidenfrost effect even over 1000 °C by integrating thermally insulating porous membranes into thermally conductive metal pillars. Despite this, there are still some unrevealed mechanisms underlying the efficient heat transfer of heterogeneous STA that are beyond the current experimental capacity, as exemplified by the invisible formation of vapor layer. Herein, we extended the understanding of heat transfer of STA by conducting a theoretical simulation using a combination of the volume of fraction model and the Lee phase change model. We revealed the critical role of surface free energy of porous membrane in promoting wettability, evaporation, and particularly the vapor evacuation dynamics of heterogeneous STA. This work not only advances our fundamental understanding of Leidenfrost effect inhabitation but also provides insight on designing heterogeneous STA with optimal heat transfer efficiency.