WOLFRAM SYSTEM MODELER
OpenTankSimple tank with inlet/outlet ports |
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Diagram
Wolfram Language
In[1]:=
SystemModel["Modelica.Fluid.Vessels.OpenTank"]
Out[1]:=
Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
Model of a tank that is open to the ambient at the fixed pressure
p_ambient.
The vector of connectors ports represents fluid ports at configurable heights, relative to the bottom of tank. Fluid can flow either out of or in to each port.
The following assumptions are made:- The tank is filled with a single or multiple-substance medium having a density higher than the density of the ambient medium.
- The fluid has uniform density, temperature and mass fractions
- No liquid is leaving the tank through the open top; the simulation breaks with an assertion if the liquid level growths over the height.
The port pressures represent the pressures just after the outlet (or just before the inlet) in the attached pipe.
The hydraulic resistances portsData.zeta_in and portsData.zeta_out determine the dissipative pressure drop between tank and port depending on
the direction of mass flow. See VesselPortsData and [Idelchik, Handbook of Hydraulic Resistance, 2004].
With the setting use_portsData=false, the port pressure represents the static head
at the height of the respective port.
The relationship between pressure drop and mass flow rate at the port must then be provided by connected components;
Heights of ports as well as kinetic and potential energy of fluid entering or leaving are not taken into account anymore.
Parameters (22)
| energyDynamics |
Value: system.energyDynamics Type: Dynamics Description: Formulation of energy balance |
|---|---|
| massDynamics |
Value: system.massDynamics Type: Dynamics Description: Formulation of mass balance |
| substanceDynamics |
Value: massDynamics Type: Dynamics Description: Formulation of substance balance |
| traceDynamics |
Value: massDynamics Type: Dynamics Description: Formulation of trace substance balance |
| p_start |
Value: p_ambient Type: AbsolutePressure (Pa) Description: Start value of pressure |
| use_T_start |
Value: true Type: Boolean Description: = true, use T_start, otherwise h_start |
| T_start |
Value: if use_T_start then system.T_start else Medium.temperature_phX(p_start, h_start, X_start) Type: Temperature (K) Description: Start value of temperature |
| h_start |
Value: if use_T_start then Medium.specificEnthalpy_pTX(p_start, T_start, X_start) else Medium.h_default Type: SpecificEnthalpy (J/kg) Description: Start value of specific enthalpy |
| X_start |
Value: Medium.X_default Type: MassFraction[Medium.nX] (kg/kg) Description: Start value of mass fractions m_i/m |
| C_start |
Value: Medium.C_default Type: ExtraProperty[Medium.nC] Description: Start value of trace substances |
| nPorts |
Value: 0 Type: Integer Description: Number of ports |
| use_portsData |
Value: true Type: Boolean Description: = false to neglect pressure loss and kinetic energy |
| portsData |
Value: Type: VesselPortsData[if use_portsData then nPorts else 0] Description: Data of inlet/outlet ports |
| m_flow_nominal |
Value: if system.use_eps_Re then system.m_flow_nominal else 1e2 * system.m_flow_small Type: MassFlowRate (kg/s) Description: Nominal value for mass flow rates in ports |
| m_flow_small |
Value: if system.use_eps_Re then system.eps_m_flow * m_flow_nominal else system.m_flow_small Type: MassFlowRate (kg/s) Description: Regularization range at zero mass flow rate |
| use_Re |
Value: system.use_eps_Re Type: Boolean Description: = true, if turbulent region is defined by Re, otherwise by m_flow_small |
| use_HeatTransfer |
Value: false Type: Boolean Description: = true to use the HeatTransfer model |
| height |
Value: Type: Height (m) Description: Height of tank |
| crossArea |
Value: Type: Area (m²) Description: Area of tank |
| p_ambient |
Value: system.p_ambient Type: AbsolutePressure (Pa) Description: Tank surface pressure |
| T_ambient |
Value: system.T_ambient Type: Temperature (K) Description: Tank surface Temperature |
| level_start |
Value: 0.5 * height Type: Height (m) Description: Start value of tank level |
Inputs (2)
Connectors (12)
 |
ports |
Type: VesselFluidPorts_b[nPorts] Description: Fluid inlets and outlets |
|---|---|---|
 |
heatPort |
Type: HeatPort_a Description: Thermal port for 1-dim. heat transfer (filled rectangular icon) |
 |
portsData_diameter_internal |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_height_internal |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_zeta_in_internal |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_zeta_out_internal |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_diameter |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_height |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_zeta_in |
Type: RealInput[nPorts] Description: 'input Real' as connector |
|
portsData_zeta_out |
Type: RealInput[nPorts] Description: 'input Real' as connector |
 |
regularFlow |
Type: BooleanInput[nPorts] Description: 'input Boolean' as connector |
|
inFlow |
Type: BooleanInput[nPorts] Description: 'input Boolean' as connector |
Components (4)
 |
system |
Type: System Description: System properties |
|---|---|---|
 |
medium |
Type: BaseProperties Description: Base properties (p, d, T, h, u, R_s, MM and, if applicable, X and Xi) of a medium |
 |
portsData |
Type: VesselPortsData[if use_portsData then nPorts else 0] Description: Data of inlet/outlet ports |
 |
heatTransfer |
Type: HeatTransfer Description: Wall heat transfer |
Used in Examples (6)
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Modelica.Fluid.Examples Simple model of a heating system |
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Modelica.Fluid.Examples.Tanks Demonstrating the usage of SimpleTank |
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Modelica.Fluid.Examples.Tanks Two tanks connected with pipes at different heights |
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Modelica.Fluid.Examples.Tanks Show the treatment of empty tanks |
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Modelica.Fluid.Examples.ControlledTankSystem Demonstrating the controller of a tank filling/emptying system |
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Modelica.Fluid.Examples.Explanatory Differences between using one port with and without explicit junction model and two port sensors for fluid temperature measuring |
Revisions
- Dec. 12, 2008 by Rüdiger Franke: move port definitions to BaseClasses.PartialLumpedVessel; also use energy and mass balance from common base class
- Dec. 8, 2008 by Michael Wetter (LBNL):
Implemented trace substances. - Jan. 6, 2006 by Katja Poschlad, Manuel Remelhe (AST Uni Dortmund),
Martin Otter (DLR):
Implementation based on former tank model. - Oct. 29, 2007 by Carsten Heinrich (ILK Dresden):
Adapted to the new fluid library interfaces:- FluidPorts_b is used instead of FluidPort_b (due to it is defined as an array of ports)
- Port name changed from port to ports
- Apr. 25, 2006 by Katrin Prölß (TUHH):
Limitation to bottom ports only, added inlet and outlet loss factors.