This work aims at a reliable prediction of the flow dynamics in stirred tanks. The focus is on the free-surface turbulent flow in an eccentric stirred tank by using the combination of detached-eddy simulation and volume of fluid model. The flow field, profiles of the free surface, mean velocities, and the macroinstability phenomenon were explored and compared with the available experimental data. A reasonable representation of the free-surface hydrodynamics was achieved. The findings indicate that the model and simulation strategies presented here can be used with sufficient confidence to predict the free-surface hydrodynamics in stirred tanks.