Suppression of Leidenfrost instability using multiple rods and rectangular mesh elements

Abstract

Large Leidenfrost drops may be unstable when their diameters exceed a critical value. Through theoretical and experimental investigations, this study explored the feasibility of suppressing Leidenfrost instability in a large container, by meshing the container or its central portion into rectangular elements. Thin rods were used to construct these rectangular elements. Leidenfrost instability was considered in four rectangular configurations. They were also the rectangular mesh elements that might be used. There were two findings. First, the diameter of the largest inscribed cylinder in a rectangular configuration was the critical dimension for determining Leidenfrost instability. Second, the threshold value of this diameter in a rectangular configuration with rod(s) was 8.9λ ± 0.7λ, where λ is the capillary length of water. It was larger than its counterparts in both a rectangular container (without the presence of a rod) and a circular container (with or without the presence of a rod), due to the strong effect of the rod in a rectangular configuration. Based on these two findings, a large rectangular container was meshed into rectangular elements using thin rods, with the diameter of the largest inscribed cylinder in each element below the threshold value. This mesh method suppressed the Leidenfrost instability in the large container.