Improved control for media-scale multipass simulations

Current media-scale multipass simulations in GeoDict/FilterDict work with a fixed amount of test dust per particle batch. This does not account properly for the transition from depth filtration to cake filtration. During depth filtration, the amount of test dust may be larger because a three-dimensional volume is available for deposition. When the surface filtration regime is entered, only a two-dimensional surface is available for deposition. With a fixed amount of test dust per particle batch, either the simulation is inefficient because the amount is chosen appropriately for the surface filtration, and many more flow fields are computed than necessary during the depth filtration, or the simulation has to be stopped after the depth filtration because too high particle concentrations would yield unrealistic overlapping particles and too high pressure drop in the cake filtration regime. The current work concerns the automatic detection of the transition from depth filtr ation to cake filtration in multipass filtration simulations and the automatic control of the simulation to account for this in terms of numbers of particles/amount of test dust deposited in a single particle batch of the multipass filter life time simulations. The old and the new methodology are compared with experiments performed on a multipass test stand.