The tapping process of a 50 t converter is simulated by using commercial software Fluent 6. 3 and based on pressure separated implicit analytic calculation and k-e bi-equation
and the simulation results is compared with the results of physical simulation with geometric similarity ratio 1: 4 water model. Results show that the numerical simulation results are compared to water model simulation results
because of neglecting the interaction of friction between liquid and wall face in numerical model
the vortex forming time and tapping time obtained by numerical simulation are less than that obtained by water model simulation; at current structure of tapping hole
the slag entrained by vortex during tapping is inevitable
and the vortex formed is most at middle and later period of tapping.