Fast mediascale multi pass simulations

For computational efficiency, current media-scale Multi Pass simulations of the Multi Pass test procedure ISO 4548-12 in ITWMs FilterDict Software work on batches of particles. Each batch consists of a fixed number of particles of test dust that are all transported based on the same flow field and that all get deposited on the same obstacle structure. The flow field is first computed for the initial fibrous obstacle structure given by the filter medium. Before each new batch previous deposited particles are added to the obstacle structure and the flow filed is updated. Now an automated control accounts for the transition from depth to cake filtration by adjusting the numbers of particles / amount of test dust deposited in a given batch. The principal features of the method approach are currently shown for a small, scholarly test example. The old and new methodologies running with MANN+HUMMELs specialized UDFs are expected to yield similar results and to compare very well with experiments performed on a Multi Pass test stand. Yet the new methodology is expected to take much less computer run time than the original method