Beschreibung:
The present study aims at modeling the pressure drop of flows through growing cakes of compressible fibrous materials, which may form on the upstream side of containment sump strainers after a loss-of-coolant accident. The model developed is based on the coupled solution of a differential equation for the change of the pressure drop in terms of superficial liquid velocity and local porosity of the fiber cake and a material equation that accounts for the compaction pressure dependent cake porosity. Details of its implementation into a general-purpose three-dimensional computational fluid dynamics code are given. An extension to this basic model is presented, which simulates the time dependent clogging of the fiber cake due to capturing of suspended particles as they pass trough the cake. The extended model relies on empirical relations, which model the change of pressure drop and removal efficiency in terms of particle deposit in the fiber cake.