WOLFRAM SYSTEMMODELER

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

Connectors (2)

ports

Type: VesselFluidPorts_b[nPorts]

Description: Fluid inlets and outlets

heatPort

Type: HeatPort_a

Components (4)

system

Type: System

Description: System properties

medium

Type: BaseProperties

portsData

Type: VesselPortsData[if use_portsData then nPorts else 0]

Description: Data of inlet/outlet ports

heatTransfer

Type: HeatTransfer

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