Public Member Functions
float	effective_area (self)
float	velocity (self)
float	feed_loss (self, float chamber_pressure)
float	stiffness (self, float chamber_pressure)
float	floor (self)
float	ceiling (self)

Public Attributes
	mdot
	area
	injector_dp

Static Public Attributes
float	supply_pressure = 0.0
tuple	band = (0.0, 0.0)

Detailed Description

One propellant's arrival at the face.

Args:
    propellant: Species name.
    mdot: Delivered mass flow [kg/s].
    density: Liquid density at the face [kg/m^3].
    area: Geometric injector area, all elements [m^2].
    cd: Discharge coefficient at this operating point [-].
    injector_dp: Pressure difference across the face [Pa].
    supply_pressure: Pressure at the tank outlet [Pa]. The head of the
        budget, so ``supply - injector_dp - p_c`` is what the plumbing ate.

Definition at line 71 of file balance.py.

Member Function Documentation

◆ ceiling()

float feedtwin.engine.balance.SideBalance.ceiling ( self )

The top of the design band, or zero when none was stated.

A real upper bound, not a formality: past it the injector is spending
tank pressure the vehicle carried structural mass to hold, and the
optimiser that chose the band was trading exactly that.

Definition at line 131 of file balance.py.

References band.

◆ effective_area()

float feedtwin.engine.balance.SideBalance.effective_area ( self )

``Cd . A`` [m^2] -- the area the flow actually sees.

Definition at line 97 of file balance.py.

References area, and feedtwin.engine.design.DischargeModel.cd().

Referenced by feedtwin.engine.component.InjectorLeg.diagnostics(), and feedtwin.engine.component.InjectorLeg.pressure_drop().

◆ feed_loss()

float feedtwin.engine.balance.SideBalance.feed_loss	(		self,
		float	chamber_pressure )

What the plumbing spent between tank outlet and face [Pa].

Zero when no supply pressure was supplied, rather than a negative
number that would read as the feed system adding pressure.

Definition at line 109 of file balance.py.

References supply_pressure.

◆ floor()

float feedtwin.engine.balance.SideBalance.floor ( self )

The stiffness this side must clear: its own band, else the rule.

Definition at line 126 of file balance.py.

References band.

◆ stiffness()

float feedtwin.engine.balance.SideBalance.stiffness	(		self,
		float	chamber_pressure )

``dp_injector / p_c`` [-]. The design rule's number.

Definition at line 119 of file balance.py.

References injector_dp.

◆ velocity()

float feedtwin.engine.balance.SideBalance.velocity ( self )

Mean injection velocity [m/s]. Sets atomisation, so it is worth
seeing next to the pressure drop rather than derived later.

Definition at line 102 of file balance.py.

References area, engine.pipeline.config_schemas.FluidConfig.density, engine.pipeline.config_schemas.StainlessSteelCaseConfig.density, and feedtwin.vessels.volume.GasVolume.density().

Member Data Documentation

◆ area

feedtwin.engine.balance.SideBalance.area

Definition at line 107 of file balance.py.

Referenced by feedtwin.engine.design.InjectorSide.cd_at(), effective_area(), feedtwin.comps.wall.LineWall.exchange(), engine.layerx.diag.start.Element.inertance(), velocity(), and engine.layerx.diag.start.Element.volume().

◆ band

tuple feedtwin.engine.balance.SideBalance.band = (0.0, 0.0)

static

Definition at line 92 of file balance.py.

Referenced by ceiling(), and floor().

◆ injector_dp

feedtwin.engine.balance.SideBalance.injector_dp

Definition at line 117 of file balance.py.

Referenced by stiffness().

◆ mdot

feedtwin.engine.balance.SideBalance.mdot

Definition at line 107 of file balance.py.

Referenced by engine.layerx.flight.InlineAscent.advance(), feedtwin.session.network_trace.NetworkTrace.append(), feedtwin.session.network_trace.NetworkTrace.record(), engine.pipeline.stability.chug.ChugStream.resistance(), and feed_line_K.Run.straight().

◆ supply_pressure

float feedtwin.engine.balance.SideBalance.supply_pressure = 0.0