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WOLFRAM SYSTEM MODELER

ClosedVolume

Volume of fixed size, closed to the ambient, with inlet/outlet ports

Diagram

Wolfram Language

In[1]:=

SystemModel["Modelica.Fluid.Vessels.ClosedVolume"]

Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Ideally mixed volume of constant size with two fluid ports and one medium model. The flow properties are computed from the upstream quantities, pressures are equal in both nodes and the medium model if use_portsData=false. Heat transfer through a thermal port is possible, it equals zero if the port remains unconnected. A spherical shape is assumed for the heat transfer area, with V=4/3*pi*r^3, A=4*pi*r^2. Ideal heat transfer is assumed per default; the thermal port temperature is equal to the medium temperature.

If use_portsData=true, 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 volume and port depending on the direction of mass flow. See VesselPortsData and [Idelchik, Handbook of Hydraulic Resistance, 2004].

Parameters (18)

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: system.p_start 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
V	Value: Type: Volume (m³) Description: Volume

Inputs (2)

fluidVolume	Default Value: V Type: Volume (m³) Description: Volume
fluidLevel	Default Value: 0 Type: Height (m) Description: Level of fluid in the vessel for treating heights of ports

fluidVolume

Default Value: V

Type: Volume (m³)

Description: Volume

fluidLevel

Default Value: 0

Type: Height (m)

Description: Level of fluid in the vessel for treating heights of ports

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 (2)

RoomCO2

Modelica.Fluid.Examples.TraceSubstances

Demonstrates a room volume with CO2 accumulation

RoomCO2WithControls

Modelica.Fluid.Examples.TraceSubstances

Demonstrates a room volume with CO2 controls