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WOLFRAM SYSTEM MODELER

SweptVolume

Varying cylindric volume depending on the position of the piston

Diagram

Wolfram Language

In[1]:=

SystemModel["Modelica.Fluid.Machines.SweptVolume"]

Out[1]:=

Information

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

Mixing volume with varying size. The size of the volume is given by:

cross sectional piston area
piston stroke given by the flange position s
clearance (volume at flange position = 0)

Losses are neglected. The shaft power is completely converted into mechanical work on the fluid.

The flange position has to be equal or greater than zero. Otherwise the simulation stops. The force of the flange results from the pressure difference between medium and ambient pressure and the cross sectional piston area. For using the component, a top level instance of the ambient model with the inner attribute is needed.

The pressure at both fluid ports equals the medium pressure in the volume. No suction nor discharge valve is included in the model.

The thermal port is directly connected to the medium. The temperature of the thermal port equals the medium temperature. The heat capacity of the cylinder and the piston are not includes in the model.

Parameters (19)

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
pistonCrossArea	Value: Type: Area (m²) Description: Cross sectional area of piston
clearance	Value: Type: Volume (m³) Description: Remaining volume at zero piston stroke

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 (13)

	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
	flange	Type: Flange_b Description: Translation flange for piston

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

Revisions

29 Oct 2007 by Carsten Heinrich:
Model added to the Fluid library