Abstract: A new induction heating method was proposed for tundish and three kinds of side-type electromagnetic induction heaters were designed. The distribution of electromagnetic force of heaters， and its effects on flow field and temperature distribution in tundish were studied by numerical simulation. The optimal heater and heating power was obtained by analyzing the RTD (residence time distribution) curve. The results show that the flow field and temperature distribution of the molten steel in the tundish are improved by moving electromagnetic induction heater towards the end of the tundish. With the same heating power， the heating effect of the U-type heater is superior to E-type heater， and compared with bilateral and symmetrical distribution of U-type heater， the unilateral U-type heater has a better thermal efficiency. Increasing the induction heating power is beneficial to improve the flow of molten steel and improve the quality of the casting. For a four-strand tundish， the heating power of 800~1000kW is enough to compensate the heat loss.

Key words: induction heating, tundish, electromagnetic field, flow field, temperature field, RTD curve