Mathematical modeling of flow field in slab continuous casting mold considering mold powder and solidified shell with high temperature quantitative measurement

Optimization of mathematical model of flow field in slab continuous casting mold was performed by means of industrial measurement and mathematical modeling. The rod deflection method was used to quantitatively measure the velocities near the mold surface at high temperature. The measurement results were compared with the simulation results of three mathematical models at different argon gas flow rates of 6, 10 and 14 L min⁻¹. The model 1 neglects the mold powder layer, thermal effect and solidified shell. The model 2 only considers the influence of mold powder layer. The model 3 considers the influence of mold powder layer, thermal effect and solidified shell on the flow field. In all three models, the diameter of argon bubbles obeys Rosin–Rammler distribution fitted according to the experimental data of others’ previous work. With increasing the argon gas flow rate, the velocity of liquid steel near the mold surface decreases. The model 1 seriously underestimates the shear stress of liquid steel near the mold surface, and its calculation results show higher velocity near the mold surface, lower turbulent kinetic energy and wider distribution of argon gas bubbles in the mold. The simulation results of model 2 only considering the viscous resistance of the mold powder layer to liquid steel makes the velocity near the surface lower than the measurement results obviously. The calculated velocities near the mold surface with model 3 are in best agreement with the measured results, showing the reasonable spatial distribution range of argon bubbles in the mold and the moderate turbulent kinetic energy. In the present conditions, the best argon gas flow rate is 10 L min⁻¹ due to the moderate velocity near the mold surface, the appropriate distribution of argon gas bubbles in the mold and the smallest fluctuation amplitude on the mold surface.