.TransiEnt.Storage.Heat.PackedBedStorage_L4.PackedBedStorage_L4.PressureLossHotAir .TransiEnt.Storage.Heat.PackedBedStorage_L4.PackedBedStorage_L4.PressureLossHotAirmodel PressureLossHotAir = ClaRa.Basics.ControlVolumes.Fundamentals.PressureLoss.Generic_PL.LinearPressureLoss_L2;