feedtwin.comps.elements.MeasuredElement Class Reference

Inheritance diagram for feedtwin.comps.elements.MeasuredElement:

Collaboration diagram for feedtwin.comps.elements.MeasuredElement:

Public Member Functions
None	__init__ (self, ComponentInstance instance)
float	pressure_drop (self, float mdot, FlowConditions flow)
dict[str, float]	diagnostics (self, float mdot, FlowConditions flow)
Public Member Functions inherited from feedtwin.comps.base.HydraulicComponent
None	__init__ (self, ComponentInstance instance)
str	id (self)
str	type (self)
float	static_head (self, FlowConditions flow)
float	total_dp (self, float mdot, FlowConditions flow)
float	signal (self, FlowConditions flow, str name, float default=1.0)
bool	isolates (self, Mapping[str, float]|None signals=None)
float|None	flow_ceiling (self, FlowConditions flow)
float|None	pinned_flow (self, float dp_available, FlowConditions flow)
bool	is_choked (self, float dp_available, FlowConditions flow)
list[Violation]	check (self)
int	n_residuals (self)
Sequence[float]	residuals (self, EvalContext ctx)
Mapping[str, float]	outputs (self, EvalContext ctx)
FlowConditions	conditions (self, PortState port, Mapping[str, float] signals)
str	__repr__ (self)

Public Attributes
Curve	curve = curve
Public Attributes inherited from feedtwin.comps.base.HydraulicComponent
	instance = instance
	p = instance.si_params()
	opt = dict(instance.options)

Additional Inherited Members
Static Public Attributes inherited from feedtwin.comps.base.HydraulicComponent
str	inlet_port = "inlet"
str	outlet_port = "outlet"
bool	symmetric = False
	conditions_provider = None

Detailed Description

Pressure drop read from a measured curve, superseding every correlation.

The component-level counterpart of the property layer's tabulated backend,
and the same principle: inside the range you measured, your data wins.

Unlike the property layer this does **not** fall through to a correlation
outside its range. A property has a defensible fallback in an equation of
state; a component's measured curve has no equivalent, and quietly
switching to a correlation halfway up a flow sweep would produce a kink
nobody asked for and nobody would see.

Off its ends it is continued quadratically (:func:`_curve_dp`, the same
continuation a measured segment gets): ``dp ~ mdot^2`` is the law the curve
is a measurement of, and it runs through zero. It used to raise there, and
flow benches rarely sweep from zero: a solve starts every branch at 1 g/s,
so a curve over 0.05-0.2 kg/s that bracketed the answer could not be
solved at all, and a capped stub's zero-flow back-fill raised out of a
solve asked not to raise. :meth:`diagnostics` flags a flow that was not
measured (``extrapolated``), so the excursion is visible, not silent.

Definition at line 820 of file elements.py.

Constructor & Destructor Documentation

__init__()

None feedtwin.comps.elements.MeasuredElement.__init__	(		self,
		ComponentInstance	instance )

Definition at line 844 of file elements.py.

References __init__().

Referenced by __init__().

Member Function Documentation

diagnostics()

dict[str, float] feedtwin.comps.elements.MeasuredElement.diagnostics	(		self,
		float	mdot,
		FlowConditions	flow )

Derived quantities worth reporting: velocity, Reynolds number, K.

Never consumed by a solver. This is what a frame and a report show, and
what makes a result inspectable rather than just a number.

Reimplemented from feedtwin.comps.base.HydraulicComponent.

Definition at line 857 of file elements.py.

References curve, and feedtwin.comps.base.HydraulicComponent.pressure_drop().

pressure_drop()

float feedtwin.comps.elements.MeasuredElement.pressure_drop	(		self,
		float	mdot,
		FlowConditions	flow )

Flow-dependent pressure loss [Pa]. Always non-negative.

A *loss*: it opposes the flow, so it lowers the downstream pressure
whichever way the fluid is going. Reverse flow is each component's own
business -- symmetric for a pipe, very much not for a check valve.

Anything that does **not** depend on the direction of flow belongs in
:meth:`static_head`, not here. See that method for why the distinction
is load-bearing rather than tidy.

Reimplemented from feedtwin.comps.base.HydraulicComponent.

Definition at line 854 of file elements.py.

References feedtwin.comps.elements._curve_dp(), and curve.

Member Data Documentation

curve

feedtwin.comps.elements.MeasuredElement.curve = curve

Definition at line 852 of file elements.py.

Referenced by diagnostics(), feedtwin.model.segments.LineSegment.has_curve(), and pressure_drop().

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The documentation for this class was generated from the following file:

• lib/feedtwin/feedtwin/comps/elements.py