Abstract: In this paper three-dimensional flow field in the molten pool between unequal diameter twin rolls has been studied by BFC technology and SIMPLEC numerical method. From the computed flow pattern,the characteristic of molten steel flow has been discussed. The dynamics generated by the feeding flow and the motivation of counter-rotating twin rolls produces a recirculating flow field nearby the small roll due to the larger room and less resistant here and fluid flows along the roll surface tangential nearby large roll and extends to two side dams. There is faintly flow around the dams of molten pool

Key words: NNSCC, strip cast-rolling, twin rolls, BFC technology, fluid flow