Package Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase
Package with utility functions to compute two phase pressure loss characteristics

Information

Standard package icon.

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

Package Contents

NameDescription
dp_twoPhaseChisholm_DPFrictional pressure loss of straight pipe for two phase flow according to Chisholm correlation | calculate pressure loss | overall flow regime
dp_twoPhaseFriedel_DPFrictional pressure loss of straight pipe for two phase flow according to Friedel correlation | calculate pressure loss| overall flow regime
dp_twoPhaseGeodetic_DPGeodetic pressure loss of straight pipe for two phase flow | calculate pressure loss
dp_twoPhaseMomentum_DPMomentum pressure loss of straight pipe for two phase flow | calculate pressure loss
SlipRatioCalculation of (analytical/empirical) slip ratio
TwoPhaseDensityCalculation of mean density for two phase flow
TwoPhaseMultiplierChisholmCalculation of two phase multiplier according to Chisholm | constant mass flow rate quality
TwoPhaseMultiplierFriedelCalculation of two phase multiplier according to Friedel | constant mass flow rate quality | horizontal flow | vertical upflow and downflow
VoidFractionCalculation of (cross sectional) void fraction for two phase flow

Function 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

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
TwoPhaseFlow_conIN_con 
TwoPhaseFlow_varIN_var 
MassFlowRatem_flowMass flow rate

Outputs

TypeNameDescription
PressureDPOutput for function dp_twoPhaseChisholm_DP

Function 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

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
TwoPhaseFlow_conIN_con 
TwoPhaseFlow_varIN_var 
MassFlowRatem_flowMass flow rate

Outputs

TypeNameDescription
PressureDPOutput for function dp_twoPhaseFriedel_DP

Function Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase.​dp_twoPhaseGeodetic_DP
Geodetic pressure loss of straight pipe for two phase flow | calculate pressure loss

Information

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
VoidFractionApproachvoidFractionApproachChoice of void fraction approach
BooleancrossSectionalAveragedtrue == cross sectional averaged void fraction | false == volumetric
LengthlengthLength in fluid flow direction
AnglephiTilt angle to horizontal
Densityrho_gDensity of gaseous phase
Densityrho_lDensity of liquid phase
Realx_flowMass flow rate quality

Outputs

TypeNameDescription
PressureDP_geoGeodetic pressure loss

Function Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase.​dp_twoPhaseMomentum_DP
Momentum pressure loss of straight pipe for two phase flow | calculate pressure loss

Information

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
VoidFractionApproachvoidFractionApproachChoice of void fraction approach
BooleanmassFlowRateCorrectionConsider heterogeneous mass flow rate correction
AreaA_crossCross sectional area
LengthperimeterPerimeter
Densityrho_gDensity of gas
Densityrho_lDensity of liquid
Realx_flow_endMass flow rate quality at end of length
Realx_flow_staMass flow rate quality at start of length
MassFlowRatem_flowMass flow rate

Outputs

TypeNameDescription
PressureDP_momMomentum pressure loss

Function 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

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
TwoPhaseFlow_conIN_con 
TwoPhaseFlow_varIN_var 
MassFlowRatem_flowMass flow rate

Outputs

TypeNameDescription
RealphiTwo phase multiplier w.r.t. Friedel

Function Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase.​TwoPhaseMultiplierChisholm
Calculation of two phase multiplier according to Chisholm | constant mass flow rate quality

Information

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
TwoPhaseFlow_conIN_con 
TwoPhaseFlow_varIN_var 
MassFlowRatem_flowMass flow rate

Outputs

TypeNameDescription
RealphiTwo phase multiplier w.r.t. Chisholm

Function 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

TypeNameDescription
VoidFractionApproachvoidFractionApproachChoice of void fraction approach
BooleanmassFlowRateCorrectionConsider heterogeneous mass flow rate correction
Densityrho_gDensity of gaseous phase
Densityrho_lDensity of liquid phase
Realepsilon_AVoid fraction (cross sectional averaged)
Realx_flowMass flow rate quality

Outputs

TypeNameDescription
Densityrho_2phMean density of two phase flow

Function Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase.​VoidFraction
Calculation of (cross sectional) void fraction for two phase flow

Information

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
VoidFractionApproachvoidFractionApproachChoice of void fraction approach
BooleancrossSectionalAveragedtrue == cross sectional averaged void fraction | false == volumetric
Densityrho_gDensity of gaseous phase
Densityrho_lDensity of liquid phase
Realx_flowMass flow rate quality

Outputs

TypeNameDescription
RealepsilonVoid fraction
RealslipRatioSlip ratio

Function Modelica.​Fluid.​Dissipation.​Utilities.​Functions.​PressureLoss.​TwoPhase.​SlipRatio
Calculation of (analytical/empirical) slip ratio

Information

This icon indicates Modelica functions.

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

Inputs

TypeNameDescription
VoidFractionApproachvoidFractionApproachChoice of void fraction approach
Densityrho_gDensity of gaseous phase
Densityrho_lDensity of liquid phase
Realx_flowMass flow rate quality

Outputs

TypeNameDescription
RealSRSlip ratio

Generated 2018-12-12 12:13:30 EST by MapleSim.