Characterization of a liquid jet from a stratified or full flow in a pipe and injected into a steam crossflow

Abstract

This study presents the physical analysis of the injection jet based on the two-phase CFD simulation of no water level and co-current steam flow pressurized thermal shock (PTS) COSI experiments. In a first step, the physical analysis deals with various aspects related to the flow characteristics at the injection outlet, such as flow configuration (stratified or full), water level, jet trajectory or breakup length in the quiescent gas. In a second step, the analysis is completed by studying the influence of steam crossflow on the jet, resulting in modifications to the jet regime, jet trajectory, breakup height and deformation, which is characterized by the jet width and angle spread. It is observed that at low flow rates, the flow in the injection is stratified. Correlations from the literature are used to characterize this flow, consistent with the simulations carried out. Analysis shows that the liquid jet remains continuous in the cold leg. The liquid jet simulated for stratified or full flow in the injection is compared satisfactorily with correlations for jets injected in a quiescent gas or in a gas crossflow. Steam crossflow strongly modifies the trajectory and shape of the jet.