.ClaRa.SubSystems.Furnace.HopperSlice_L4_AdditionalAir.ParticleMigration .ClaRa.SubSystems.Furnace.HopperSlice_L4_AdditionalAir.ParticleMigrationmodel ParticleMigration = ClaRa.Components.Furnace.GeneralTransportPhenomena.ParticleMigration.FixedMigrationSpeed_simple(w_fixed = 10);