.ClaRa.SubSystems.Furnace.ConvectiveSlice_L4.GasHeatTransfer_Wall .ClaRa.SubSystems.Furnace.ConvectiveSlice_L4.GasHeatTransfer_Wallmodel GasHeatTransfer_Wall = ClaRa.Basics.ControlVolumes.Fundamentals.HeatTransport.Gas_HT.Convection.Convection_flatWall_L2;