Experimental and theoretical studies of rewetting of unheated/heated grooved plates

摘要

Theoretical experimental investigations of the rewetting characteristics of thin liquid films over unheated and heated grooved plates were performed. Studied factors which affected the rewetting characteristics of the plate were mass flow rate of the rewetting liquid on the plate, the orientation of the plate (face up, face down or inclined) and smooth/groove surface conditions. The initial plate temperature was also varied, with experiments being performed between room temperature and 150 C. It was found that the rewetting velocity increased with the initial plate temperature. But when the temperature was increased further above the Leidenfrost temperature (liquid front temperature), the rewetting velocity decreases with the initial plate temperature. Hydrodynamically controlled and conductively controlled rewetting models were presented to explain and to predict the rewetting characteristics in these two distinct regions. Also found was a higher rewetting velocity when the grooved plate was placed in the face up orientation than in the face down orientation.