.TRANSFORM.HeatExchangers.GenericDistributed_HX_Rwall.FlowModel_tube .TRANSFORM.HeatExchangers.GenericDistributed_HX_Rwall.FlowModel_tubemodel FlowModel_tube = TRANSFORM.Fluid.ClosureRelations.PressureLoss.Models.DistributedPipe_1D.SinglePhase_Developed_2Region_NumStable;