PartialTwoPortTransport

Partial element transporting fluid between two ports without storage of mass or energy

Information

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

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 dp and the mass flow rate m_flow,
port_b.h_outflow for flow in design direction, and
port_a.h_outflow for flow in reverse direction.

Moreover appropriate values shall be assigned to the following parameters:

dp_start for a guess of the pressure drop
m_flow_small for regularization of zero flow.

Parameters (6)

allowFlowReversal	Value: system.allowFlowReversal Type: Boolean Description: = true to allow flow reversal, false restricts to design direction (port_a -> port_b)
dp_start	Value: 0.01 * system.p_start Type: AbsolutePressure (Pa) Description: Guess value of dp = port_a.p - port_b.p
m_flow_start	Value: system.m_flow_start Type: MassFlowRate (kg/s) Description: Guess value of m_flow = port_a.m_flow
m_flow_small	Value: if system.use_eps_Re then system.eps_m_flow * system.m_flow_nominal else system.m_flow_small Type: MassFlowRate (kg/s) Description: Small mass flow rate for regularization of zero flow
show_T	Value: true Type: Boolean Description: = true, if temperatures at port_a and port_b are computed
show_V_flow	Value: true Type: Boolean Description: = true, if volume flow rate at inflowing port is computed

Connectors (2)

	port_a	Type: FluidPort_a Description: Fluid connector a (positive design flow direction is from port_a to port_b)
	port_b	Type: FluidPort_b Description: Fluid connector b (positive design flow direction is from port_a to port_b)

port_a

Type: FluidPort_a

Description: Fluid connector a (positive design flow direction is from port_a to port_b)

port_b

Type: FluidPort_b

Description: Fluid connector b (positive design flow direction is from port_a to port_b)

Components (3)

	system	Type: System Description: System wide properties
	state_a	Type: ThermodynamicState Description: state for medium inflowing through port_a
	state_b	Type: ThermodynamicState Description: state for medium inflowing through port_b

system

Type: System

Description: System wide properties

state_a

Type: ThermodynamicState

Description: state for medium inflowing through port_a

state_b

Type: ThermodynamicState

Description: state for medium inflowing through port_b

Extended by (9)

	PartialPressureLoss Modelica.Fluid.Interfaces Base flow model for pressure loss functions with the same area at port_a and at port_b
	BaseModelNonconstantCrossSectionArea Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent Generic pressure drop component with constant turbulent loss factor data and without an icon, for non-constant cross section area
	BaseModel Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent Generic pressure drop component with constant turbulent loss factor data and without an icon
	SimpleGenericOrifice Modelica.Fluid.Fittings Simple generic orifice defined by pressure loss coefficient and diameter (only for flow from port_a to port_b)
	VolumeFlowRate Modelica.Fluid.Fittings.GenericResistances Flow model for generic resistance parameterized with the volume flow rate
	PartialValve Modelica.Fluid.Valves.BaseClasses Base model for valves
	ValveDiscrete Modelica.Fluid.Valves Valve for water/steam flows with linear pressure drop
	ValveLinear Modelica.Fluid.Valves Valve for water/steam flows with linear pressure drop
	TestWallFrictionAndGravity Modelica.Fluid.Pipes.BaseClasses.WallFriction Pressure loss in pipe due to wall friction and gravity (only for test purposes; if needed use Pipes.StaticPipe instead)