Experimental investigation of a submerged air–water bubbly flow jet in a water tank as a model of steel casting

Small-scale air–water experiments reported here contain all the important features of the industrial caster, the mold feed pipe, and the nozzles associated with it. The liquid is introduced into the feed pipe through an annulus with the gas entering at the center. The liquid travels down the walls of the feed pipe as a film until it encounters the pipe section containing a two-phase (air–water) bubbly mixture. Drift-flux relations are derived to compute the flow parameters (gas void fraction, horizontal velocity of the jet, etc.), which are found to be in good agreement with observations. The direction of the two-phase bubbly jet emerging from the nozzle is quantified, showing an improved downward deflection angle.