Evaluation of the performance of cavities in nucleate boiling at microscale level

Nucleate boiling heat transfer (NBHT) from enhanced structures is an effective way to dissipate a high heat flux. In the present study, the behavior of cavities with nucleation on roughened surfaces is studied numerically during the entire ebullition cycle based on the phase-change lattice Boltzmann method. The adopted model is firstly validated by the Laplace law and the two-phase coexistence curve and then is applied to investigate the effects of the cavity structure on NBHT. The bubble departure diameter, departure frequency, and the total boiling heat flux of the ebullition cycle are also studied. It is shown that the cavity widths and the cavity grooves exhibit a significant influence on the NBHT features. A cavity with a circular groove in the present research shows the best performance for NBHT in terms of the averaged heat flux and bubble release frequency. When a specific cavity is combined with other different cavities on roughened surfaces, its nucleation process on different roughened surfaces may differ greatly.