Investigation of single bubble rising velocity in LBE by transparent liquids similarity experiments

Based on the pool type lead-based reactor, the two-phase flow phenomenon remains a longstanding challenge in a Steam Generator Tube Rupture (SGTR) scenario. In order to investigate the bubble rising velocity in opaque liquid Lead Bismuth Eutectic (LBE), experiments were carried out by injecting argon gas into four transparent liquids (water, glycerol, alcohol and FC-3283). The appropriate drag coefficient of a single bubble was obtained by dimensionless Eötvos number under different liquids. For bubble equivalent diameter from 4 mm to 6 mm, the bubble flow located in the regime of surface tension dominant, where the bubble terminal rising velocity tended to a value almost independent of the bubble diameter. The single bubble rising velocity remained about 0.252 m/s to 0.274 m/s in gas-liquid metal bubbly flow. An appropriate modified correlation was recommended to roughly forecast the single bubble terminal rising velocity in two phase flow with high liquid-to-gas density ratio. These data can provide a reference on analyzing bubble migration process under accident condition.