test_rupe_criterion Namespace Reference

Functions
	_python_physics ()
	_cfg (**geom)
	_em_eq4 (cfg, diag, mdot_O, mdot_F)
	solved ()
	test_rupe_M_is_reported_and_is_elverum_morey_eq4 (solved)
	test_R_is_the_cd_dp_ratio_it_always_was (solved)
	test_6500N_design_point_is_lox_dominant ()
	test_M_carries_the_hole_size_R_does_not ()

Variables
	ROOT = Path(__file__).resolve().parents[1]
float	PSI = 6894.757
float	P_TANK = 584.2669657943025 * PSI

Detailed Description

Rupe's mixing criterion for an unlike doublet, reported by the impinging solve.

Rupe (JPL PR 20-195 / 20-209), restated by Elverum & Morey, JPL Memo 30-5 (1959) eq. 1: the
most uniform mixture-ratio distribution of a one-on-one unlike doublet occurs at

    M = rho_O v_O^2 d_O / (rho_F v_F^2 d_F) = 1,

and eq. 4 gives the same number in flow terms, (rho_F/rho_O)(mdot_O/mdot_F)^2 (d_F/d_O)^3 per
element pair. The solver's ``momentum_ratio_R`` is sqrt(rho_O v_O^2 / rho_F v_F^2); with
mdot = Cd A sqrt(2 rho dp), rho v^2 = 2 Cd^2 dp, so R is (Cd_O/Cd_F) sqrt(dp_O/dp_F) exactly --
no density, no hole size, and not Rupe's criterion.

Expected values here come from eq. 4 on the solved flows, not from the module's own formula.

Function Documentation

_cfg()

test_rupe_criterion._cfg ( ** geom )

protected

Definition at line 41 of file test_rupe_criterion.py.

Referenced by solved(), and test_6500N_design_point_is_lox_dominant().

_em_eq4()

test_rupe_criterion._em_eq4 ( cfg, diag, mdot_O, mdot_F )

protected

Definition at line 54 of file test_rupe_criterion.py.

Referenced by test_6500N_design_point_is_lox_dominant(), and test_rupe_M_is_reported_and_is_elverum_morey_eq4().

_python_physics()

test_rupe_criterion._python_physics ( )

protected

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

Definition at line 28 of file test_rupe_criterion.py.

solved()

test_rupe_criterion.solved

(

)

Definition at line 62 of file test_rupe_criterion.py.

References _cfg().

test_6500N_design_point_is_lox_dominant()

test_rupe_criterion.test_6500N_design_point_is_lox_dominant

(

)

The shipped holes at the solved design point: M 1.21 (hand, from v_O 32.61 / v_F 37.22 m/s,
d_O 1.548 / d_F 1.421 mm), where R 1.05 reads as balanced.

Definition at line 83 of file test_rupe_criterion.py.

References _cfg(), and _em_eq4().

test_M_carries_the_hole_size_R_does_not()

test_rupe_criterion.test_M_carries_the_hole_size_R_does_not

(

)

Same injector dp on both sides, larger LOX hole: M grows with d_O, R does not see it.

Definition at line 94 of file test_rupe_criterion.py.

test_R_is_the_cd_dp_ratio_it_always_was()

test_rupe_criterion.test_R_is_the_cd_dp_ratio_it_always_was

(

solved

)

Definition at line 75 of file test_rupe_criterion.py.

test_rupe_M_is_reported_and_is_elverum_morey_eq4()

test_rupe_criterion.test_rupe_M_is_reported_and_is_elverum_morey_eq4

(

solved

)

Definition at line 69 of file test_rupe_criterion.py.

References _em_eq4().

Variable Documentation

P_TANK

float test_rupe_criterion.P_TANK = 584.2669657943025 * PSI

Definition at line 24 of file test_rupe_criterion.py.

PSI

float test_rupe_criterion.PSI = 6894.757

Definition at line 23 of file test_rupe_criterion.py.

ROOT

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

Definition at line 22 of file test_rupe_criterion.py.