modelNozzle

Model for dynamic pressure difference

Extends from ThermofluidStream.Interfaces.SISOFlow (Base Model with basic flow eqautions for SISO).

Information

Implementation of a nozzle taking gas dynamic effects into account.

By default, the density is assumed to be constant across the component. This assumption can be reverted by setting assumeConstantDensity = false and hence the outlet velocity is computed by the outlet density. Beware that this will lead to a non-linear equation system in the component.

By definition, the sign of the velocity matches the sign of the mass-flow rate at the inlet.

Parameters

TypeNameDefaultDescription
StringinstanceName (from DropOfCommonsPlus)getInstanceName()Instance name
BooleanassumeConstantDensitytrue= true, if incompressibility is assumed (use '= false' for Ma > 0.3)
BooleandA_indisplayParameters and displayInletArea and not area_in_FromInputDisplay inlet area
BooleandA_outdisplayParameters and displayOutletArea and not area_out_FromInputDisplay outlet area
BooleandisplayAdA_in or dA_outDisplay inlet area or display outlet area
StringAreaStringif dA_in and dA_out then "A_in=%A_in, A_out=%A_out" elseif dA_in and not dA_out then "A_in = %A_in" elseif not dA_in and dA_out then "A_out = %A_out" else ""
StringcompressibilityStringif assumeConstantDensity then "incompressible" else "compressible"
StringdisplayPos1if displayCompressibilityApproach then compressibilityString elseif displayA then AreaString elseif displayInertance then "L = %L_value" else ""
StringdisplayPos2if displayCompressibilityApproach and displayA then AreaString elseif displayInertance and not displayPos1 == "L = %L" then "L = %L_value" else ""
StringdisplayPos3if displayCompressibilityApproach and displayA and displayInertance then "L = %L_value" else ""
Layout
BooleandisplayInstanceName (from DropOfCommonsPlus)dropOfCommons.displayInstanceNames= true, if instance name is displayed
BooleandisplayParameters (from DropOfCommonsPlus)dropOfCommons.displayParameters= true, if displaying parameters is enabled
Advanced
BooleanconsiderInertance (from SISOFlow)dropOfCommons.considerInertance=true, if transient momentum (inertance) term is considered; disable only for advanced use
Utilities.Units.InertanceL (from SISOFlow)dropOfCommons.LInertance
StateSelectm_flowStateSelect (from SISOFlow)StateSelect.defaultState selection for mass flow rate
Booleanclip_p_out (from SISOFlow)= false, if dr_corr=0 (correction of inertial pressure difference)
Medium.AbsolutePressurep_min (from SISOFlow)dropOfCommons.p_minMinimum steady-state output pressure
ThermofluidStream.Utilities.Units.InertanceL_valuedropOfCommons.LInertance
Initialization › Mass flow rate
InitializationMethodsinitM_flow (from SISOFlow)ThermofluidStream.Utilities.Types.InitializationMethods.noneInitialization method for mass flow rate
SI.MassFlowRatem_flow_0 (from SISOFlow)0Initial value for mass flow rate
Utilities.Units.MassFlowAccelerationm_acceleration_0 (from SISOFlow)0Initial value for derivative of mass flow rate
Nozzle / Diffusor definition
Booleanarea_in_FromInputfalse= true, if input connector for inlet cross section area is enabled
SI.AreaA_in1Inlet cross-sectional area
Booleanarea_out_FromInputfalse= true, if input connector for outlet cross section area is enabled
SI.AreaA_out1Outlet cross-sectional area
Layout › Display parameters
BooleandisplayCompressibilityApproachtrue= true, if assumeConstantDensity is displayed
BooleandisplayInletAreatrue= true, if inlet area A_in is displayed
BooleandisplayOutletAreatrue= true, if outlet area A_out is displayed
BooleandisplayInertancefalse=true, if inertance L is displayed

Connectors

TypeNameDefaultDescription
Inletinlet (from SISOFlow)
Outletoutlet (from SISOFlow)
Modelica.Blocks.Interfaces.RealInputA_in_varInlet cross-sectional area input connector [m2]
Modelica.Blocks.Interfaces.RealInputA_out_varOutlet cross-sectional area input connector [m2]

Components

TypeNameDefaultDescription
SI.MassFlowRatem_flow (from SISOFlow)inlet.m_flowMass flow rate
SI.Pressuredr_corr (from SISOFlow)Correction of inertial pressure difference
SI.Pressuredp (from SISOFlow)Pressure difference
Medium.AbsolutePressurep_in (from SISOFlow)Medium.pressure(inlet.state)Inlet pressure
Medium.SpecificEnthalpyh_in (from SISOFlow)Medium.specificEnthalpy(inlet.state)Inlet specific enthalpy
Medium.MassFraction[Medium.nXi]Xi_in (from SISOFlow)Medium.massFraction(inlet.state)Inlet mass fractions
Medium.AbsolutePressurep_out (from SISOFlow)Outlet pressure
Medium.SpecificEnthalpyh_out (from SISOFlow)Outlet specific enthalpy
Medium.MassFraction[Medium.nXi]Xi_out (from SISOFlow)Outlet mass fractions