According to the structure and process parameters of a 40 t six-strand heavy rail steel tundish in a steel mill

the flow field

temperature field and RTD curve are studied through numerical simulation of Ansys Fluent software. It is found that the distribution of flow field and temperature field in the original tundish is unreasonable and the flow consistency is poor. Through the orthogonal experiments

the optimized scheme of an elevation angle of 10° at the bottom

an elevation angle of 10° in the middle

and a 0 mm upward movement of the opening of the retaining wall is determined. The simulation results show that through the optimized design

the overall flow field velocity of the tundish is increased

the standard deviation of the average residence time of molten steel is greatly reduced

the lowest temperature is increased by 14. 2 K

the temperature difference of each nozzle is reduced by 1.77 K

and the consistency of each flow is significantly enhanced. The production application results for casting U75V heavy rail steel by 40 t tundish shows that after optimization the forthest nozzle （out3） average residence time reduces from original 687. 1 s to 575. 5 s

the difference of temperature of each nozzle flow decreases from original 2. 05 K to 0. 28 K to improve obviously.