Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase

Package with utility functions to compute two phase pressure loss characteristics

Information

Extends from Modelica.Icons.FunctionsPackage (Icon for packages containing functions).

Package Content

Name Description
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseChisholm_DP dp_twoPhaseChisholm_DP Frictional pressure loss of straight pipe for two phase flow according to Chisholm correlation | calculate pressure loss | overall flow regime
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseFriedel_DP dp_twoPhaseFriedel_DP Frictional pressure loss of straight pipe for two phase flow according to Friedel correlation | calculate pressure loss| overall flow regime
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseGeodetic_DP dp_twoPhaseGeodetic_DP Geodetic pressure loss of straight pipe for two phase flow | calculate pressure loss
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseMomentum_DP dp_twoPhaseMomentum_DP Momentum pressure loss of straight pipe for two phase flow | calculate pressure loss
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierFriedel TwoPhaseMultiplierFriedel Calculation of two phase multiplier according to Friedel | constant mass flow rate quality | horizontal flow | vertical upflow and downflow
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierChisholm TwoPhaseMultiplierChisholm Calculation of two phase multiplier according to Chisholm | constant mass flow rate quality
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseDensity TwoPhaseDensity Calculation of mean density for two phase flow
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.VoidFraction VoidFraction Calculation of (cross sectional) void fraction for two phase flow
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.SlipRatio SlipRatio Calculation of (analytical/empirical) slip ratio

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseChisholm_DP Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseChisholm_DP

Frictional pressure loss of straight pipe for two phase flow according to Chisholm correlation | calculate pressure loss | overall flow regime

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
Constant inputs
IN_con 
Variable inputs
IN_var 
Input
m_flowMass flow rate [kg/s]

Outputs

NameDescription
DPOutput for function dp_twoPhaseChisholm_DP [Pa]

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseFriedel_DP Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseFriedel_DP

Frictional pressure loss of straight pipe for two phase flow according to Friedel correlation | calculate pressure loss| overall flow regime

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
Constant inputs
IN_con 
Variable inputs
IN_var 
Input
m_flowMass flow rate [kg/s]

Outputs

NameDescription
DPOutput for function dp_twoPhaseFriedel_DP [Pa]

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseGeodetic_DP Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseGeodetic_DP

Geodetic pressure loss of straight pipe for two phase flow | calculate pressure loss

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
voidFractionApproachChoice of void fraction approach
crossSectionalAveragedtrue == cross sectional averaged void fraction | false == volumetric
Geometry
lengthLength in fluid flow direction [m]
phiTilt angle to horizontal [rad]
Fluid properties
rho_gDensity of gaseous phase [kg/m3]
rho_lDensity of liquid phase [kg/m3]
x_flowMass flow rate quality

Outputs

NameDescription
DP_geoGeodetic pressure loss [Pa]

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseMomentum_DP Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseMomentum_DP

Momentum pressure loss of straight pipe for two phase flow | calculate pressure loss

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
Choices
voidFractionApproachChoice of void fraction approach
massFlowRateCorrectionConsider heterogeneous mass flow rate correction
Geometry
A_crossCross sectional area [m2]
perimeterPerimeter [m]
Fluid properties
rho_gDensity of gas [kg/m3]
rho_lDensity of liquid [kg/m3]
x_flow_endMass flow rate quality at end of length
x_flow_staMass flow rate quality at start of length
Input
m_flowMass flow rate [kg/s]

Outputs

NameDescription
DP_momMomentum pressure loss [Pa]

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierFriedel Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierFriedel

Calculation of two phase multiplier according to Friedel | constant mass flow rate quality | horizontal flow | vertical upflow and downflow

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
Constant inputs
IN_con 
Variable inputs
IN_var 
Input
m_flowMass flow rate [kg/s]

Outputs

NameDescription
phiTwo phase multiplier w.r.t. Friedel

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierChisholm Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierChisholm

Calculation of two phase multiplier according to Chisholm | constant mass flow rate quality

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
Constant inputs
IN_con 
Variable inputs
IN_var 
Input
m_flowMass flow rate [kg/s]

Outputs

NameDescription
phiTwo phase multiplier w.r.t. Chisholm

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseDensity Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseDensity

Calculation of mean density for two phase flow

Information

The gaseous and the liquid part of a fluid in a two phase flow are often discontinuously distributed. This complex behaviour is simplified for engineering calculations. The two phase flow of different fluid flow situations (e.g., bubble or stratified flow) is modelled as if the gaseous and the liquid phase are continuously distributed.

A mean density assuming a continuous distribution out of a discontinuous two phase fluid flow situation can be calculated with a homogeneous or a heterogeneous approach (see dp_twoPhaseOverall_DP).

The following modelling approaches can be used to calculate the mean density of two phase flow:

The heterogeneous approaches are analytically derived by minimising the momentum flux or the kinetic energy flow assuming implicitly that the two-phase flow will tend towards the minimum of this quantity.

References

VDI:
VDI - Wärmeatlas: Berechnungsblätter für den Wärmeübergang. Springer Verlag, 10th edition, 2006.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
rho_gDensity of gaseous phase [kg/m3]
rho_lDensity of liquid phase [kg/m3]
epsilon_AVoid fraction (cross sectional averaged)
x_flowMass flow rate quality
Choices
voidFractionApproachChoice of void fraction approach
massFlowRateCorrectionConsider heterogeneous mass flow rate correction

Outputs

NameDescription
rho_2phMean density of two phase flow [kg/m3]

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.VoidFraction Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.VoidFraction

Calculation of (cross sectional) void fraction for two phase flow

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
crossSectionalAveragedtrue == cross sectional averaged void fraction | false == volumetric
rho_gDensity of gaseous phase [kg/m3]
rho_lDensity of liquid phase [kg/m3]
x_flowMass flow rate quality
Choices
voidFractionApproachChoice of void fraction approach

Outputs

NameDescription
epsilonVoid fraction
slipRatioSlip ratio

Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.SlipRatio Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.SlipRatio

Calculation of (analytical/empirical) slip ratio

Information

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

NameDescription
rho_gDensity of gaseous phase [kg/m3]
rho_lDensity of liquid phase [kg/m3]
x_flowMass flow rate quality
Choices
voidFractionApproachChoice of void fraction approach

Outputs

NameDescription
SRSlip ratio
Automatically generated Thu Dec 19 17:20:12 2019.