The blast furnace (BF) hearth’s condition is crucial for a long and healthy campaign life. Previous numerical investigations on BF drainage commonly treated the deadman as a static, porous medium. In this work, we employ a coupled computational fluid dynamics (CFD) – discrete element method (DEM) to account for its dynamic behavior. The model is utilized in several short-term simulations to generate a database of deadman states based on iron and slag levels, coke properties and the burden weight distribution. In contrast to the previous Eulerian deadman descriptions, we directly obtain an inhomogeneous description of the porosity from a particle size distribution. The database is utilized in the dynamic void fraction model, to describe the transient deadman in a fully Eulerian framework for long-term simulations. In essence, we present a strategy to mitigate the coupling between the dynamics of a packed bed and the fluid flow through it by connecting the bed’s evolution to global state parameters such as the levels of liquids in which the particles float. This methodology is not restricted to blast furnaces, but can also be applied to other problems involving slow granular motion with dynamic interstitial fluids.