modelNozzle

Model of a variable throat-area nozzle operating in subsonic or supersonic conditions.
Diagram of NozzleOpen the diagram
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Parameters

TypeNameDefaultDescription
Modelica.SIunits.AreaAfull5e-7Cross-sectional area of the fully open valve
RealXopen1Opening if no external command is connected (0=fully closed; 1=fully open)
BooleanCompute_ChokedFlowtrueThe computation of the choked conditions at the throat can be disabled if the nozzle always operate in subsonic conditions
BooleanUse_gammafalseUse a fictitious gamma (perfect gas model) to compute the critical pressure (not valid in liquid or two-phase!)
Initialization
Medium.AbsolutePressureP_su_start17E5Start value for the inlet pressure
Medium.TemperatureT_su_start273.15 + 150Start value for the inlet pressure
Medium.AbsolutePressureP_ex_start2E5Start value for the inlet pressure
Realgamma_start1.05Start value of the fictitious expansion factor, used to compute the start value of the critical pressure
Medium.AbsolutePressurep_choked_startP_su_start*(2/(gamma_start + 1))^(gamma_start/(gamma_start - 1))Critical throat pressure start value

Connectors

TypeNameDefaultDescription
ThermoCycle.Interfaces.Fluid.FlangeAsu
ThermoCycle.Interfaces.Fluid.FlangeBex
Modelica.Blocks.Interfaces.RealInputcmd

Components

TypeNameDefaultDescription
Medium.ThermodynamicStateinlet
Medium.ThermodynamicStateinlet_start
Medium.ThermodynamicStatethroat_start
Medium.ThermodynamicStatethroat
Medium.ThermodynamicStatethroat_choked
Modelica.SIunits.AreaAValve throat area
Medium.AbsolutePressureDELTAp_00.05e5Minimum pressure drop below which a linear flow dependency is assumed
Medium.AbsolutePressurep_thr
Medium.AbsolutePressurep_su
Medium.SpecificEntropys_su
Medium.AbsolutePressurep_choked
Modelica.SIunits.VolumeFlowRateV_dot_leak
Modelica.SIunits.VelocityC_thr
Modelica.SIunits.MassFlowRateMdot_thr
Modelica.SIunits.MassFlowRateMdot_choked
RealgammaEquivalent isentropic expansion factor

Contents

NameDescription
Medium