Study of Controlled Condensation Implosion Events

At LEI (Lithuanian Energy Institute) an experimental program has been initiated to investigate the ‘condensation implosion’ phenomena that can occur for horizontally stratified liquid-vapour flow conditions. The goal is understand the critical boundary conditions sufficiently so that the phenomenon can be controlled and initiated at will. After a reliable ‘pulser’ is developed, the follow up goal is to implement this unique component in a thermal-hydraulic system designed to perform certain tasks, e.g. to pump water or to transport energy passively in a downward direction. Experimental data obtained to data has shown that pulsers can be designed in which the vapour-liquid interface perturbation required for the initiation of condensation implosions is generated internally and depends solely on the rate at which liquid is supplied to the pulser. Data is presented which documents the conditions required for transition from a smooth to a wavy interface, and subsequently to an exponentially increasing surface distortion that culminates in a ‘condensation implosion’. The importance of the shear-stress generated by the condensation rate is illustrated.