modelSweptVolume
Varying cylindric volume depending on the position of the piston
Extends from Modelica.Fluid.Vessels.BaseClasses.PartialLumpedVessel (Lumped volume with a vector of fluid ports and replaceable heat transfer model).
Information
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
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Area | pistonCrossArea | Cross sectional area of piston | |
| SI.Volume | clearance | Remaining volume at zero piston stroke | |
| SI.ReynoldsNumber | Re_turbulent (from PartialLumpedVessel) | 100 | cf. suddenExpansion |
| Assumptions › Dynamics | |||
| Types.Dynamics | energyDynamics (from PartialLumpedVolume) | system.energyDynamics | Formulation of energy balance |
| Types.Dynamics | massDynamics (from PartialLumpedVolume) | system.massDynamics | Formulation of mass balance |
| Types.Dynamics | substanceDynamics (from PartialLumpedVolume) | massDynamics | Formulation of substance balance |
| Types.Dynamics | traceDynamics (from PartialLumpedVolume) | massDynamics | Formulation of trace substance balance |
| Initialization | |||
| Medium.AbsolutePressure | p_start (from PartialLumpedVolume) | system.p_start | Start value of pressure |
| Boolean | use_T_start (from PartialLumpedVolume) | true | = true, use T_start, otherwise h_start |
| Medium.Temperature | T_start (from PartialLumpedVolume) | if use_T_start then system.T_start else Medium.temperature_phX(p_start, h_start, X_start) | Start value of temperature |
| Medium.SpecificEnthalpy | h_start (from PartialLumpedVolume) | if use_T_start then Medium.specificEnthalpy_pTX(p_start, T_start, X_start) else Medium.h_default | Start value of specific enthalpy |
| Medium.MassFraction[Medium.nX] | X_start (from PartialLumpedVolume) | Medium.X_default | Start value of mass fractions m_i/m |
| Medium.ExtraProperty[Medium.nC] | C_start (from PartialLumpedVolume) | Medium.C_default | Start value of trace substances |
| General › Ports | |||
| Integer | nPorts (from PartialLumpedVessel) | 0 | Number of ports |
| Boolean | use_portsData (from PartialLumpedVessel) | true | = false to neglect pressure loss and kinetic energy |
| Modelica.Fluid.Vessels.BaseClasses.VesselPortsData | portsData (from PartialLumpedVessel) | Data of inlet/outlet ports | |
| Advanced › Port properties | |||
| Medium.MassFlowRate | m_flow_nominal (from PartialLumpedVessel) | if system.use_eps_Re then system.m_flow_nominal else 1e2*system.m_flow_small | Nominal value for mass flow rates in ports |
| SI.MassFlowRate | m_flow_small (from PartialLumpedVessel) | if system.use_eps_Re then system.eps_m_flow*m_flow_nominal else system.m_flow_small | Regularization range at zero mass flow rate |
| Boolean | use_Re (from PartialLumpedVessel) | system.use_eps_Re | = true, if turbulent region is defined by Re, otherwise by m_flow_small |
| Assumptions › Heat transfer | |||
| Boolean | use_HeatTransfer (from PartialLumpedVessel) | false | = true to use the HeatTransfer model |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| VesselFluidPorts_b[nPorts] | ports (from PartialLumpedVessel) | Fluid inlets and outlets | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort (from PartialLumpedVessel) | ||
| Modelica.Mechanics.Translational.Interfaces.Flange_b | flange | Translation flange for piston |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Volume | V | Fluid volume | |
| Modelica.Fluid.System | system (from PartialLumpedVolume) | System properties | |
| SI.Volume | fluidVolume (from PartialLumpedVolume) | Volume | |
| Medium.BaseProperties | medium (from PartialLumpedVolume) | ||
| SI.Energy | U (from PartialLumpedVolume) | Internal energy of fluid | |
| SI.Mass | m (from PartialLumpedVolume) | Mass of fluid | |
| SI.Mass | mXi (from PartialLumpedVolume) | Masses of independent components in the fluid | |
| SI.Mass | mC (from PartialLumpedVolume) | Masses of trace substances in the fluid | |
| Medium.ExtraProperty[Medium.nC] | C (from PartialLumpedVolume) | Trace substance mixture content | |
| SI.MassFlowRate | mb_flow (from PartialLumpedVolume) | Mass flows across boundaries | |
| SI.MassFlowRate | mbXi_flow (from PartialLumpedVolume) | Substance mass flows across boundaries | |
| Medium.ExtraPropertyFlowRate | mbC_flow (from PartialLumpedVolume) | Trace substance mass flows across boundaries | |
| SI.EnthalpyFlowRate | Hb_flow (from PartialLumpedVolume) | Enthalpy flow across boundaries or energy source/sink | |
| SI.HeatFlowRate | Qb_flow (from PartialLumpedVolume) | Heat flow across boundaries or energy source/sink | |
| SI.Power | Wb_flow (from PartialLumpedVolume) | Work flow across boundaries or source term | |
| Medium.EnthalpyFlowRate[nPorts] | ports_H_flow (from PartialLumpedVessel) | ||
| Medium.MassFlowRate[nPorts,Medium.nXi] | ports_mXi_flow (from PartialLumpedVessel) | ||
| Medium.MassFlowRate | sum_ports_mXi_flow (from PartialLumpedVessel) | Substance mass flows through ports | |
| Medium.ExtraPropertyFlowRate[nPorts,Medium.nC] | ports_mC_flow (from PartialLumpedVessel) | ||
| Medium.ExtraPropertyFlowRate | sum_ports_mC_flow (from PartialLumpedVessel) | Trace substance mass flows through ports | |
| HeatTransfer | heatTransfer (from PartialLumpedVessel) | ||
| Medium.Density | portInDensities (from PartialLumpedVessel) | Densities of the fluid at the device boundary | |
| SI.Velocity | portVelocities (from PartialLumpedVessel) | Velocities of fluid flow at device boundary | |
| SI.EnergyFlowRate | ports_E_flow (from PartialLumpedVessel) | Flow of kinetic and potential energy at device boundary | |
| Real | s (from PartialLumpedVessel) | Curve parameters for port flows vs. port pressures; for further details see, Modelica Tutorial: Ideal switching devices | |
| Real | ports_penetration (from PartialLumpedVessel) | Penetration of port with fluid, depending on fluid level and port diameter | |
| SI.Area | portAreas (from PartialLumpedVessel) | {Modelica.Constants.pi/4*portsData_diameter[i]^2 for i in 1:nPorts} | |
| Medium.AbsolutePressure | vessel_ps_static (from PartialLumpedVessel) | Static pressures inside the vessel at the height of the corresponding ports, zero flow velocity | |
| SI.MassFlowRate | m_flow_turbulent (from PartialLumpedVessel) |
Revisions
- 29 Oct 2007
by Carsten Heinrich:
Model added to the Fluid library