Marangoni effect and heat pipe dry-out

Abstract

In this study, Marangoni flows effects on heat pipe performances are explored. Recent results dealing with computations of the meniscus shape in a wedge are extended to take into account a nonzero flow rate, caused by the liquid mass lost at the evaporator and supplied by the vapor condensation at the opposite side. Moreover “inverse Marangoni effects” (prevailing in some binary mixtures) are investigated. Dry-out conditions have been computed for different flow rates and surface tension gradients. Results show that while dry-out occurrence is anticipated by the usual Marangoni effect, as illustrated by Yang and Homsy [Phys. Fluids18, 042107 (2006)], an inverse Marangoni effect is beneficial and dry-out conditions are delayed at much larger heating rates.