modelSmoothedInit

SmoothedInit: Smooth transitions between the different flow regimes including an initialisation and a filtering

Extends from BaseClasses.PartialConvectiveSmoothed (Smoothed heat transfer coefficients).

Information

The model SmoothedInit extends the partial model PartialConvectiveSmoothed and allows the user to choose the correlation to calculate the heat transfer coefficient in the different zones:

  • liquidCorrelation: correlation for the liquid zone. The user can choose between the ones listed in SinglePhaseCorrelations
  • twoPhaseCorrelation : correlation for the two-phase zone. The user can choose between the ones listed in TwoPhaseCorrelations
  • vaporCorrelation: correlation for the vapor zone.The user can choose between the ones listed in SinglePhaseCorrelations

In order to increase the robustness of the model an initialization option is available:the heat transfer coefficient value is initialized with the nominal value defined by the user U_nom, and after a certain time (t_init - see below) the value is smoothed to the one calculated with the correlations previusly defined by the user.

In cases of fluctuating pressures and chattering, applying a first order filter to the change in heat transfer coefficient increases stability, set the parameter filterConstant > 0 to activate it.

A limiter for the maximum change of the heat transfer coefficent with respect to time can be activated by setting the parameter max_dUdt >=0 in the general tab.

In the Initialization tab the following options are availabe:

    • t_start: start time for Initialization
    • t_init: duration of the Initialization
  • Parameters

    TypeNameDefaultDescription
    Integern (from PartialHeatTransfer)1Number of heat transfer segments
    RealsmoothingRange (from PartialConvectiveSmoothed)0.2Vapour quality smoothing range
    RealmassFlowExp (from PartialConvectiveSmoothed)0.8Mass flow correction term, disable with 0.0
    Initialization
    Modelica.SIunits.Timet_start5Start of initialization
    Modelica.SIunits.Timet_init5Duration of initialization
    Correlations
    Modelica.SIunits.TimefilterConstant0Integration time of filter, 0=disabled
    Realmax_dUdt10000maximum change in HTC, 0=disabled

    Connectors

    TypeNameDefaultDescription
    Interfaces.HeatTransfer.ThermalPortLthermalPortL (from PartialHeatTransfer)

    Components

    TypeNameDefaultDescription
    Medium.ThermodynamicStateFluidState (from PartialHeatTransfer)Thermodynamic states of flow segments
    Modelica.SIunits.HeatFluxq_dot (from PartialHeatTransfer)Heat flux
    Modelica.SIunits.TemperatureT_fluid (from PartialHeatTransfer)Medium.temperature(FluidState)Temperature of the fluid for the heat transfer process
    Modelica.SIunits.MassFlowRateMdotnom (from PartialConvectiveCorrelation)Nomnial Mass flow rate
    Modelica.SIunits.CoefficientOfHeatTransferUnom_l (from PartialConvectiveCorrelation)Nominal heat transfer coefficient liquid side
    Modelica.SIunits.CoefficientOfHeatTransferUnom_tp (from PartialConvectiveCorrelation)nominal heat transfer coefficient two phase side
    Modelica.SIunits.CoefficientOfHeatTransferUnom_v (from PartialConvectiveCorrelation)nominal heat transfer coefficient vapor side
    Modelica.SIunits.MassFlowRateM_dot (from PartialConvectiveCorrelation)Inlet massflow
    Realx (from PartialConvectiveCorrelation)Vapor quality
    Modelica.SIunits.CoefficientOfHeatTransferU (from PartialConvectiveSmoothed)
    Modelica.SIunits.CoefficientOfHeatTransferU_nom_LTP (from PartialConvectiveSmoothed)
    Modelica.SIunits.CoefficientOfHeatTransferU_nom_TPV (from PartialConvectiveSmoothed)
    Modelica.SIunits.CoefficientOfHeatTransferU_nom (from PartialConvectiveSmoothed)
    RealLTP (from PartialConvectiveSmoothed)
    RealTPV (from PartialConvectiveSmoothed)
    RealLV (from PartialConvectiveSmoothed)
    RealmassFlowFactor (from PartialConvectiveSmoothed)
    Realx_L (from PartialConvectiveSmoothed)
    Realx_LTP (from PartialConvectiveSmoothed)
    Realx_TPV (from PartialConvectiveSmoothed)
    Realx_V (from PartialConvectiveSmoothed)Vapor quality
    Realdivisor (from PartialConvectiveSmoothed)10
    RealdUdt_limiter
    Modelica.SIunits.CoefficientOfHeatTransferU_limited
    Modelica.SIunits.CoefficientOfHeatTransferU_filtered
    Modelica.SIunits.CoefficientOfHeatTransferU_initialized
    Realinitialized
    Modelica.SIunits.CoefficientOfHeatTransferU_cor_l
    Modelica.SIunits.CoefficientOfHeatTransferU_cor_tp
    Modelica.SIunits.CoefficientOfHeatTransferU_cor_v
    LiquidCorrelationliquidCorrelation
    TwoPhaseCorrelationtwoPhaseCorrelation
    VapourCorrelationvapourCorrelation
    Modelica.SIunits.CoefficientOfHeatTransferU_cor_LTP
    Modelica.SIunits.CoefficientOfHeatTransferU_cor_TPV
    Modelica.SIunits.CoefficientOfHeatTransferU_cor
    Medium.ThermodynamicStatestate
    Medium.ThermodynamicStatestate_L
    Medium.ThermodynamicStatestate_TP
    Medium.ThermodynamicStatestate_Vthe different states
    Medium.SpecificEnthalpyh_bub_TP
    Medium.SpecificEnthalpyh_dew_TP
    Medium.SpecificEnthalpyh_bub_L
    Medium.SpecificEnthalpyh_dew_V
    Medium.SpecificEnthalpydelta_h
    Medium.SpecificEnthalpyh_bub
    Medium.SpecificEnthalpyh_dewChanged bubble and dew state enthalpies
    Medium.AbsolutePressurep
    Medium.SpecificEnthalpyh
    Medium.SpecificEnthalpyh_L
    Medium.SpecificEnthalpyh_V
    Medium.SpecificEnthalpyh_TP

    Contents

    NameDescription
    LiquidCorrelation
    TwoPhaseCorrelation
    VapourCorrelation