modelMultiFlow1D

1-D fluid flow model. The Cells are in parallel and a pressure drop is considered
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Information

This model describes the flow of a constant heat capacity fluid in parallel pipes. Each pipe is represented by the lumped model. It is obtained by connecting in parallel N AirCell The resulting discretization scheme is of the staggered type i.e. state variables are computed at the center of each cell and the node variables are calculated depending on the local discretization (Upwind or Central difference).

Parameters

TypeNameDefaultDescription
IntegerN10number of Cells
Modelica.SIunits.VolumeV_f0.0397Total volume of fluid
Modelica.SIunits.AreaA_f2.7Total Lateral surface
BooleanUseNomfalseUse Nominal conditions to compute pressure drop characteristics
Modelica.SIunits.Lengthh0Static fluid head (dp = h * rho * g)
Realk38.4E3*9.5Coefficient for linear pressure drop (dp = k * V_dot)
Modelica.SIunits.AreaA(2*9.5*23282.7)^(-0.5)Valve throat area for quadratic pressure drop (dp = 1/A?*M_dot?/(2*rho))
Modelica.SIunits.PressureDELTAp_0500Pressure drop below which a 3rd order interpolation is used for the computation of the flow rate in order to avoid infinite derivative at 0
Nominal Conditions
Modelica.SIunits.MassFlowRateMdotnom2Nominal fluid flow rate
Modelica.SIunits.CoefficientOfHeatTransferUnom100Constant heat transfer coefficient
Modelica.SIunits.Pressurep_nom1e5Nominal pressure
Modelica.SIunits.TemperatureT_nom423.15Nominal temperature
Modelica.SIunits.Densityrho_nomMedium.density_pT(p_nom, T_nom)Nominal density
Modelica.SIunits.PressureDELTAp_stat_nom0Nominal static pressure drop
Modelica.SIunits.PressureDELTAp_lin_nom0Nominal linear pressure drop
Modelica.SIunits.PressureDELTAp_quad_nom0Nominal quadratic pressure drop
Booleanuse_rho_nomfalseUse the nominal density for the computation of the pressure drop (i.e it depends only the flow rate)
Initialization
Booleanconstinitfalseif true, sets the pressure drop to a constant value at the beginning of the simulation in order to avoid oscillations
BooleanUseHomotopyfalseif true, uses homotopy to set the pressure drop to zero in the first initialization
Modelica.SIunits.PressureDELTAp_startDELTAp_stat_nom + DELTAp_lin_nom + DELTAp_quad_nomStart Value for the pressure drop
Modelica.SIunits.Timet_init10if constinit is true, time during which the pressure drop is set to the constant value DELTAp_start

Connectors

TypeNameDefaultDescription
ThermoCycle.Interfaces.Fluid.FlangeAflangeA
ThermoCycle.Interfaces.Fluid.FlangeBflangeB
ThermoCycle.Interfaces.HeatTransfer.ThermalPortLthermalPortCell

Components

TypeNameDefaultDescription
Modelica.Fluid.Fittings.MultiPortmultiPort
Modelica.Fluid.Fittings.MultiPortmultiPort1
ThermoCycle.Components.FluidFlow.Pipes.AirCellsimpleAirCell
ThermoCycle.Components.Units.PdropAndValves.DPdP

Contents

NameDescription
Medium
MultiFlow1DimHeatTransferModel