dp_twoPhaseChisholm_DP
dp_twoPhaseFriedel_DP
dp_twoPhaseGeodetic_DP
dp_twoPhaseMomentum_DP
TwoPhaseMultiplierFriedel
TwoPhaseMultiplierChisholm
TwoPhaseDensity
VoidFraction
SlipRatio
Package with utility functions to compute two phase pressure loss characteristics
Extends from Modelica.Icons.FunctionsPackage (Icon for packages containing functions).
| Name | Description |
|---|---|
| dp_twoPhaseChisholm_DP
|
Frictional pressure loss of straight pipe for two phase flow according to Chisholm correlation | calculate pressure loss | overall flow regime |
| dp_twoPhaseFriedel_DP
|
Frictional pressure loss of straight pipe for two phase flow according to Friedel correlation | calculate pressure loss| overall flow regime |
| dp_twoPhaseGeodetic_DP
|
Geodetic pressure loss of straight pipe for two phase flow | calculate pressure loss |
| dp_twoPhaseMomentum_DP
|
Momentum pressure loss of straight pipe for two phase flow | calculate pressure loss |
| TwoPhaseMultiplierFriedel
|
Calculation of two phase multiplier according to Friedel | constant mass flow rate quality | horizontal flow | vertical upflow and downflow |
| TwoPhaseMultiplierChisholm
|
Calculation of two phase multiplier according to Chisholm | constant mass flow rate quality |
| TwoPhaseDensity
|
Calculation of mean density for two phase flow |
| VoidFraction
|
Calculation of (cross sectional) void fraction for two phase flow |
| SlipRatio
|
Calculation of (analytical/empirical) slip ratio |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseChisholm_DPFrictional pressure loss of straight pipe for two phase flow according to Chisholm correlation | calculate pressure loss | overall flow regime
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| Constant inputs | |
| IN_con | |
| Variable inputs | |
| IN_var | |
| Input | |
| m_flow | Mass flow rate [kg/s] |
| Name | Description |
|---|---|
| DP | Output for function dp_twoPhaseChisholm_DP [Pa] |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseFriedel_DPFrictional pressure loss of straight pipe for two phase flow according to Friedel correlation | calculate pressure loss| overall flow regime
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| Constant inputs | |
| IN_con | |
| Variable inputs | |
| IN_var | |
| Input | |
| m_flow | Mass flow rate [kg/s] |
| Name | Description |
|---|---|
| DP | Output for function dp_twoPhaseFriedel_DP [Pa] |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseGeodetic_DPGeodetic pressure loss of straight pipe for two phase flow | calculate pressure loss
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| voidFractionApproach | Choice of void fraction approach |
| crossSectionalAveraged | true == cross sectional averaged void fraction | false == volumetric |
| Geometry | |
| length | Length in fluid flow direction [m] |
| phi | Tilt angle to horizontal [rad] |
| Fluid properties | |
| rho_g | Density of gaseous phase [kg/m3] |
| rho_l | Density of liquid phase [kg/m3] |
| x_flow | Mass flow rate quality |
| Name | Description |
|---|---|
| DP_geo | Geodetic pressure loss [Pa] |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.dp_twoPhaseMomentum_DPMomentum pressure loss of straight pipe for two phase flow | calculate pressure loss
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| Choices | |
| voidFractionApproach | Choice of void fraction approach |
| massFlowRateCorrection | Consider heterogeneous mass flow rate correction |
| Geometry | |
| A_cross | Cross sectional area [m2] |
| perimeter | Perimeter [m] |
| Fluid properties | |
| rho_g | Density of gas [kg/m3] |
| rho_l | Density of liquid [kg/m3] |
| x_flow_end | Mass flow rate quality at end of length |
| x_flow_sta | Mass flow rate quality at start of length |
| Input | |
| m_flow | Mass flow rate [kg/s] |
| Name | Description |
|---|---|
| DP_mom | Momentum pressure loss [Pa] |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierFriedelCalculation of two phase multiplier according to Friedel | constant mass flow rate quality | horizontal flow | vertical upflow and downflow
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| Constant inputs | |
| IN_con | |
| Variable inputs | |
| IN_var | |
| Input | |
| m_flow | Mass flow rate [kg/s] |
| Name | Description |
|---|---|
| phi | Two phase multiplier w.r.t. Friedel |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseMultiplierChisholmCalculation of two phase multiplier according to Chisholm | constant mass flow rate quality
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| Constant inputs | |
| IN_con | |
| Variable inputs | |
| IN_var | |
| Input | |
| m_flow | Mass flow rate [kg/s] |
| Name | Description |
|---|---|
| phi | Two phase multiplier w.r.t. Chisholm |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.TwoPhaseDensityCalculation of mean density for two phase flow
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.
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| rho_g | Density of gaseous phase [kg/m3] |
| rho_l | Density of liquid phase [kg/m3] |
| epsilon_A | Void fraction (cross sectional averaged) |
| x_flow | Mass flow rate quality |
| Choices | |
| voidFractionApproach | Choice of void fraction approach |
| massFlowRateCorrection | Consider heterogeneous mass flow rate correction |
| Name | Description |
|---|---|
| rho_2ph | Mean density of two phase flow [kg/m3] |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.VoidFractionCalculation of (cross sectional) void fraction for two phase flow
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| crossSectionalAveraged | true == cross sectional averaged void fraction | false == volumetric |
| rho_g | Density of gaseous phase [kg/m3] |
| rho_l | Density of liquid phase [kg/m3] |
| x_flow | Mass flow rate quality |
| Choices | |
| voidFractionApproach | Choice of void fraction approach |
| Name | Description |
|---|---|
| epsilon | Void fraction |
| slipRatio | Slip ratio |
Modelica.Fluid.Dissipation.Utilities.Functions.PressureLoss.TwoPhase.SlipRatioCalculation of (analytical/empirical) slip ratio
Extends from Modelica.Icons.Function (Icon for functions).
| Name | Description |
|---|---|
| rho_g | Density of gaseous phase [kg/m3] |
| rho_l | Density of liquid phase [kg/m3] |
| x_flow | Mass flow rate quality |
| Choices | |
| voidFractionApproach | Choice of void fraction approach |
| Name | Description |
|---|---|
| SR | Slip ratio |