WOLFRAM SYSTEMMODELER

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

Connectors (3)

ports

Type: VesselFluidPorts_b[nPorts]

Description: Fluid inlets and outlets

heatPort

Type: HeatPort_a

flange

Type: Flange_b

Description: translation flange for piston

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