test_manifold_velocity_head Namespace Reference

Functions
	_python_physics ()
	_hand (area, mdot, rho, dp, inlets=1, f=0.05)
	test_velocity_head_function_is_the_sizing_rule ()
	solved ()
	_codes (out)
	test_6500N_channels_are_flagged_with_the_area_they_need (solved)
	test_a_channel_big_enough_is_not_flagged (solved)
	test_without_flows_the_area_ratio_is_still_reported ()

Variables
	ROOT = Path(__file__).resolve().parents[1]
str	C6500 = ROOT / "configs/ethalox_6500N.yaml"
float	PSI = 6894.757

Detailed Description

The back-face channels are the manifold, and their velocity head is checked against the
injector drop.

Holes fed from a cross-flowing channel see the channel's STATIC pressure; with the approach
flow normal to the hole axis none of the channel's velocity head is recovered (Rohde, Richards
& Metger, NASA TN D-5467, 1969), and Elverum & Morey (JPL Memo 30-5) ask for as uniform a
manifold flow as possible. Sizing rule: the channel's velocity head at the inlet, q_ch, is a
small fraction f of the injector dp, i.e. A_ch >= mdot_branch / sqrt(2 rho f dp); one inlet
per channel splits two ways, mdot_branch = mdot / 2.

On the 6500N the channels are 22.8 / 24.0 mm^2 against 45 / 38 mm^2 of orifices, so q_ch is
~63 % / 40 % of dp (config audit H-1: at least 81 / 68 mm^2 for f = 5 %). The layout used to
report the area ratio at 'info' and nothing read it.

Expected values are hand arithmetic on the layout's channel area and the solved flows.

Function Documentation

_codes()

test_manifold_velocity_head._codes ( out )

protected

Definition at line 76 of file test_manifold_velocity_head.py.

Referenced by test_6500N_channels_are_flagged_with_the_area_they_need(), test_a_channel_big_enough_is_not_flagged(), and test_without_flows_the_area_ratio_is_still_reported().

_hand()

test_manifold_velocity_head._hand ( area, mdot, rho, dp, inlets = 1, f = 0.05 )

protected

Definition at line 44 of file test_manifold_velocity_head.py.

Referenced by test_6500N_channels_are_flagged_with_the_area_they_need(), and test_velocity_head_function_is_the_sizing_rule().

_python_physics()

test_manifold_velocity_head._python_physics ( )

protected

The authoritative Python path; engine/accel mirrors it and test_numba_ab_parity holds the
two together.

Definition at line 31 of file test_manifold_velocity_head.py.

solved()

test_manifold_velocity_head.solved

(

)

Definition at line 64 of file test_manifold_velocity_head.py.

test_6500N_channels_are_flagged_with_the_area_they_need()

test_manifold_velocity_head.test_6500N_channels_are_flagged_with_the_area_they_need

(

solved

)

Definition at line 80 of file test_manifold_velocity_head.py.

References _codes(), and _hand().

test_a_channel_big_enough_is_not_flagged()

test_manifold_velocity_head.test_a_channel_big_enough_is_not_flagged

(

solved

)

Definition at line 97 of file test_manifold_velocity_head.py.

References _codes().

test_velocity_head_function_is_the_sizing_rule()

test_manifold_velocity_head.test_velocity_head_function_is_the_sizing_rule

(

)

Definition at line 51 of file test_manifold_velocity_head.py.

References _hand().

test_without_flows_the_area_ratio_is_still_reported()

test_manifold_velocity_head.test_without_flows_the_area_ratio_is_still_reported

(

)

Definition at line 107 of file test_manifold_velocity_head.py.

References _codes().

Variable Documentation

C6500

str test_manifold_velocity_head.C6500 = ROOT / "configs/ethalox_6500N.yaml"

Definition at line 26 of file test_manifold_velocity_head.py.

PSI

float test_manifold_velocity_head.PSI = 6894.757

Definition at line 27 of file test_manifold_velocity_head.py.

ROOT

test_manifold_velocity_head.ROOT = Path(__file__).resolve().parents[1]

Definition at line 25 of file test_manifold_velocity_head.py.