.ClaRa.SubSystems.Furnace.ConvectiveSlice_L4.GasHeatTransfer_TubeBundle .ClaRa.SubSystems.Furnace.ConvectiveSlice_L4.GasHeatTransfer_TubeBundlemodel GasHeatTransfer_TubeBundle = ClaRa.Basics.ControlVolumes.Fundamentals.HeatTransport.Gas_HT.Convection.Convection_tubeBank_L2;