The quality of continuously cast slabs largely depends on the processes taking place in the mold. In continuous casting of copper and its alloys the solidification process is almost completed within it. This paper presents a comprehensive optimization of the submerged entry nozzle design by combining physical and mathematical modeling with further comparison of obtained results with the actual process. The article studies the critical features of hydrodynamic processes in copper slab by physical and mathematical modeling during continuous casting. To ensure the efficiency of liquid pool homogenization, it seems appropriate to direct some metal upwards through openings in the SEN to the liquid meniscus. The optimal configuration of the SEN is the one where 35% of the liquid flows upwards to heat the melt meniscus and slab upper corner zones and 65% of liquid metal moves downward to the liquid pool bottom.