Variables
float	STUDY_LOCKUP_PSIA = 564.7
	reason
str	FIXTURE = Path(__file__).parent / "fixtures" / "ethalox_6500N_doublet_cad_2026-09-28.yaml"
str	GN2 = "copv_study_gn2"
float	PSI = 6894.757293168361
	pytestmark

Detailed Description

The drawing's feed written into the design the injector is sized with.

EngineDesign sizes the injector at lockup less one K per side. The drawing's tank does not hold
lockup while firing (regulator droop, the press line), and its lines are not the design's K. The
fit expresses both in the design's own form; checked against the twin, not against itself:

* the design as it stands misses the twin's manifold pressure by more than 7 psi on each side;
* with the fitted K0, EngineDesign's own forward solve at lockup lands on the twin's burn: its
  flows within 1.5 %, its O/F within 0.5 %;
* writing the fit into the design does not move Layer X's burn, which never used the design's K0.

Function Documentation

◆ _with()

test_layerx_feedfit._with	(		config,
			update )

protected

Definition at line 57 of file test_layerx_feedfit.py.

Referenced by test_with_the_fit_enginedesign_lands_on_the_burn(), and test_writing_the_fit_does_not_move_layer_x().

◆ burned()

test_layerx_feedfit.burned	(		config,
			drawing )

Definition at line 50 of file test_layerx_feedfit.py.

◆ config()

test_layerx_feedfit.config ( void )

Definition at line 40 of file test_layerx_feedfit.py.

◆ drawing()

test_layerx_feedfit.drawing ( )

Definition at line 45 of file test_layerx_feedfit.py.

◆ test_a_k0_that_is_not_a_loss_is_never_offered_for_the_design()

test_layerx_feedfit.test_a_k0_that_is_not_a_loss_is_never_offered_for_the_design ( )

LE4 (6), flown on helium: its LOX side is drawn with no line (tank, OM-R, injector) and the
regulator's outlet climbs as the bottle empties, so the fit came out at K0 -0.448, and the Record
page offered to write it into the design (D-58). A loss coefficient at or below zero is refused,
in words, side by side; a positive one is written as before.

Definition at line 119 of file test_layerx_feedfit.py.

◆ test_the_design_misses_the_drawings_manifold()

test_layerx_feedfit.test_the_design_misses_the_drawings_manifold ( burned )

Definition at line 66 of file test_layerx_feedfit.py.

◆ test_the_study_fit_is_writable()

test_layerx_feedfit.test_the_study_fit_is_writable ( burned )

Definition at line 140 of file test_layerx_feedfit.py.

◆ test_the_update_is_the_lumped_path_with_its_record()

test_layerx_feedfit.test_the_update_is_the_lumped_path_with_its_record ( burned )

Definition at line 99 of file test_layerx_feedfit.py.

◆ test_with_the_fit_enginedesign_lands_on_the_burn()

test_layerx_feedfit.test_with_the_fit_enginedesign_lands_on_the_burn	(		burned,
			config )

Definition at line 80 of file test_layerx_feedfit.py.

References _with().

◆ test_writing_the_fit_does_not_move_layer_x()

test_layerx_feedfit.test_writing_the_fit_does_not_move_layer_x	(	burned,
		config,
		drawing )

Layer X burns through the drawing's lines and samples EngineDesign with its feed zeroed, so
the design's K0 is not in its burn: written in, the burn is the same burn.

Definition at line 110 of file test_layerx_feedfit.py.

References _with().

Variable Documentation

◆ FIXTURE

str test_layerx_feedfit.FIXTURE = Path(__file__).parent / "fixtures" / "ethalox_6500N_doublet_cad_2026-09-28.yaml"

Definition at line 30 of file test_layerx_feedfit.py.

◆ GN2

str test_layerx_feedfit.GN2 = "copv_study_gn2"

Definition at line 31 of file test_layerx_feedfit.py.

◆ PSI

float test_layerx_feedfit.PSI = 6894.757293168361

Definition at line 34 of file test_layerx_feedfit.py.

◆ pytestmark

test_layerx_feedfit.pytestmark

Initial value:

1= pytest.mark.skipif(not (shipped_drawings_dir() / f"{GN2}.json").is_file(),

2 reason="feed-twin's shipped drawings are not next to this checkout")

Definition at line 35 of file test_layerx_feedfit.py.

◆ reason

test_layerx_feedfit.reason

Definition at line 23 of file test_layerx_feedfit.py.

◆ STUDY_LOCKUP_PSIA

float test_layerx_feedfit.STUDY_LOCKUP_PSIA = 564.7

Definition at line 21 of file test_layerx_feedfit.py.

Functions
	config ()
	drawing ()
	burned (config, drawing)
	_with (config, update)
	test_the_design_misses_the_drawings_manifold (burned)
	test_with_the_fit_enginedesign_lands_on_the_burn (burned, config)
	test_the_update_is_the_lumped_path_with_its_record (burned)
	test_writing_the_fit_does_not_move_layer_x (burned, config, drawing)
	test_a_k0_that_is_not_a_loss_is_never_offered_for_the_design ()
	test_the_study_fit_is_writable (burned)

Functions

Variables