In order to evaluate whether the existing design of submerged nozzle is reasonable or not

the simulation test on liquid level fluctuation and impact depth of flow in 230 mm x (900 ~2 150) mm mold with casting speed 0. 8 ~ 1.7 m/min is earned out by using geometric similarity 1: 2 water model. Results show that for current mold of five different cross sections

the liquid level is relatively stable and the wave height in model is no more than 1. 5 mm (corresponding prototype within 3 mm)

the slag level is stable and the distribution of molten slag layer is relatively uniform； but as for smaller cross-section slab with lower casting speed even if the impact depth is lower the liquid level fluctuation is less than 0. 5 mm (corresponding prototype less than 1.0 mm) led to lack of activity of slag-steel interface

bad melting of slag

and even causing shell of liquid surface

therefore it is necessary to re\ amp and optimize the current submerged nozzle.