Molecular dynamics investigation of the effect of nanostructured surfaces on flow boiling

Abstract

As a prominent limiting factor in the performance of microelectronic devices, the improvement of heat dissipation is of utmost importance. The enhancement of heat and mass transfer during boiling by nanostructured surfaces has been demonstrated in many studies. In this study, a nanoscale flow-boiling model is developed by molecular dynamics method in order to deeply investigate the microscopic mechanism of nanostructure-enhanced heat transfer. Simple liquid argon is heated by grooved substrate to explore the effect of the depth of the cavities on the boiling heat transfer. The results indicate that the grooved surface improves heat transfer performance through two key mechanisms. Firstly, it induces bubble nucleation, and secondly, it delays the onset of film boiling. The presence of cavities allows the argon atoms within to absorb additional energy from the surrounding walls and be in closer proximity to the heating layer. This reduction in solid thermal resistance results in increased heat transfer efficiency, leading to earlier bubble nucleation and a greater propensity for nucleation within the cavities. The low horizontal velocity of argon atoms within the cavities suggests their ability to retain a significant number of atoms, thereby effectively mitigating the deterioration of heat transfer caused by the formation of a vapor film on the solid wall. The comprehensive performance is observed to improve with increasing depth of the cavities within the range investigated in this study.