Monoporous micropillar wick structures, II-optimization & theoretical limits

This article, the second of a two-part study, is aimed at finding optimal micropillar wick geometries and their theoretical performance limits. For the first time, the theoretical optimization results are experimentally verified. The permeability and capillary pressure models determined in the first part of this study are utilized in the optimization process. First, the existence of optimality is ascertained through constrained parametric sweeps of the individual variables in the wick performance model, which reveal the presence of optimal values of each variable for a specific combination of the other variables. Then, the overall optimization of wicks is accomplished through a genetic algorithm. It is established that a unique optimal geometry, i.e. a combination of diameter, spacing and height, exists at each wicking length. Finally, these results are used to determine the theoretical performance limits of micropillar array wicks. The results suggest that the theoretical performance limit is 3–4 times greater than the highest performance reported in literature.