modelPartialTwoPortTransport
Partial element transporting fluid between two ports without storage of mass or energy
Extends from PartialTwoPort (Partial component with two ports).
Information
This component transports fluid between its two ports, without storing mass or energy.
Energy may be exchanged with the environment though, e.g., in the form of work.
PartialTwoPortTransport is intended as base class for devices like orifices, valves and simple fluid machines.
Three equations need to be added by an extending class using this component:
- the momentum balance specifying the relationship between the pressure drop
dpand the mass flow ratem_flow, port_b.h_outflowfor flow in design direction, andport_a.h_outflowfor flow in reverse direction.
Moreover appropriate values shall be assigned to the following parameters:
dp_startfor a guess of the pressure dropm_flow_smallfor regularization of zero flow.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPort) | system.allowFlowReversal | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Advanced | |||
| Medium.AbsolutePressure | dp_start | 0.01*system.p_start | Guess value of dp = port_a.p - port_b.p |
| Medium.MassFlowRate | m_flow_start | system.m_flow_start | Guess value of m_flow = port_a.m_flow |
| Medium.MassFlowRate | m_flow_small | if system.use_eps_Re then system.eps_m_flow*system.m_flow_nominal else system.m_flow_small | Small mass flow rate for regularization of zero flow |
| Advanced › Diagnostics | |||
| Boolean | show_T | true | = true, if temperatures at port_a and port_b are computed |
| Boolean | show_V_flow | true | = true, if volume flow rate at inflowing port is computed |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPort) | Fluid connector a (positive design flow direction is from port_a to port_b) | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_b (from PartialTwoPort) | Fluid connector b (positive design flow direction is from port_a to port_b) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.System | system (from PartialTwoPort) | System wide properties | |
| Medium.MassFlowRate | m_flow | Mass flow rate in design flow direction | |
| SI.Pressure | dp | Pressure difference between port_a and port_b (= port_a.p - port_b.p) | |
| SI.VolumeFlowRate | V_flow | m_flow/Modelica.Fluid.Utilities.regStep(m_flow, Medium.density(state_a), Medium.density(state_b), m_flow_small) | Volume flow rate at inflowing port (positive when flow from port_a to port_b) |
| Medium.Temperature | port_a_T | Modelica.Fluid.Utilities.regStep(port_a.m_flow, Medium.temperature(state_a), Medium.temperature(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow)), m_flow_small) | Temperature close to port_a, if show_T = true |
| Medium.Temperature | port_b_T | Modelica.Fluid.Utilities.regStep(port_b.m_flow, Medium.temperature(state_b), Medium.temperature(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow)), m_flow_small) | Temperature close to port_b, if show_T = true |