With established three-dimensional coupled numerical models for flow and heat transfer of liquid steel in tundish

the effect of immersion depth of long nozzle (100 〜200 mm) on flow field and temperature field of Q235B liquid steel (0. 12% ~0. 20% C) in a 36t tundish during casting of three strands profiled bloom for H-shaped section has been simulated and studied by using software FLUENT. Results show that with increasing the immersion depth of long nozzle the fluctuating of free surface of liquid steel in tundish has decreasing tend and the difference of average residence time and the difference of temperature of liquid steel at tundish each strand outlet obviously increase; and the suitable immersion depth of long nozzle for the tundish during profiled bloom concasting is about 125 mm.