Principally, fluid flow pattern in the tundish has important character during the operational conditions such as removing non-metallic inclusions and mixing control. Type of design and geometrical shape of tundish are effective parameters on fluid flow pattern of molten steel in the tundish. In this research, different designing of tundish configuration are considered for achievement to a tundish configuration with optimization of intermix and removing inclusions. With combination of different fluid control devices such as: weir, dam, baffle and turbo stopper, different configuration are suggested for tundish. Furthermore, a mathematical mixing model is designed and free parameters of the model related to each configuration of tundish are determined by a physical model of tundish with one quarter of real scale. Then, residence time distribution curve of each configuration is plotted and characterization of fluid flow pattern is investigated by the mathematical model prediction results. With comparison of RTD curves of different tundish configuration, the best case for fluid flow pattern when is used turbo stopper with a pair of dams as both maximum flotation of inclusions and minimum amount of intermix are evidenced.