BUBBLE RISE DYNAMICS IN WATER COLUMN
The bubble dynamics and life time inside liquid metal (sodium, NaK) has to be studied from Sodium-cooled Fast Reactor safety point of view due to the associated heat and mass transfer processes. The bubble rise dynamics in liquid metal can be studied using water, based on the similarity of transport properties. A water based experimental facility with single bubble generating system was developed to simulate the liquid metal two phase bubble flow. In the experiment, single bubble was generated in water using syringe based gas injection system. The liquid column was equipped with a rotating hemi-spherical cup, which was mounted above the gas injection system, to generate larger gas bubble volumes. The bubble rise velocity was measured using in-house developed void sensors positioned along the pool height. The experimental study is carried out to measure bubble rise velocity in a water column for various equivalent bubble diameters and aspect ratios of water column. The experimentally measured bubble rise velocity was observed to increase with increase in initial bubble diameter. The experimental results were also validated with available correlations and in-house developed numerical model. The rise velocity and bubble behavior from simulated water experiments will be useful in predicting the dynamics of single bubbles rising in liquid metal based on the similarity.