thrust_model_comparison Namespace Reference

Functions
	cea_obj (cfg)
	cea_refs (ch, Pc_pa, MR, eps, Pa_pa)
	one_case (runner, ch, P_O_pa, P_F_pa, Pa_pa, eps_override=None)
	fmt_row (label, r)
	main ()

Variables
float	G0 = 9.80665
float	PSI = 6894.76
list	CONFIGS

Detailed Description

Read-only thrust-model comparison harness (Step 1 of the thrust-bug investigation).

For a set of configs, operating points, expansion ratios, and ambient pressures, compare
three thrust numbers WITHOUT touching any production code:

  1. MODEL    — engine/core/nozzle.py momentum + shifting reconstruction (runner.evaluate).
  2. CF_VAC   — F(Pa) = Cf_vac * Pc * At - Pa * Ae, with Cf_vac from CEA at the model's real Pc.
                Efficiency rides in through Pc (the chamber solve already reduced it by eta_c*).
  3. CEA ref  — CEA's ideal equilibrium ambient Isp (the ceiling) and eta_c**ideal (physical target).

The claim under test: delivered Isp must be <= eta_c* * Isp_ideal. The MODEL instead sits at the
ideal ceiling; the CF_VAC method should land at eta_c**ideal.

Run:  ED_ACCEL=off python scripts/thrust_model_comparison.py

Function Documentation

cea_obj()

thrust_model_comparison.cea_obj

(

cfg

)

Definition at line 37 of file thrust_model_comparison.py.

Referenced by main().

cea_refs()

thrust_model_comparison.cea_refs	(		ch,
			Pc_pa,
			MR,
			eps,
			Pa_pa )

CEA ideal numbers at the model's real operating point.

Definition at line 41 of file thrust_model_comparison.py.

Referenced by one_case().

fmt_row()

thrust_model_comparison.fmt_row	(		label,
			r )

Definition at line 82 of file thrust_model_comparison.py.

Referenced by main().

main()

thrust_model_comparison.main

(

)

Definition at line 90 of file thrust_model_comparison.py.

References cea_obj(), fmt_row(), main(), and one_case().

Referenced by main().

one_case()

thrust_model_comparison.one_case	(		runner,
			ch,
			P_O_pa,
			P_F_pa,
			Pa_pa,
			eps_override = None )

Definition at line 54 of file thrust_model_comparison.py.

References cea_refs().

Referenced by main().

Variable Documentation

CONFIGS

list thrust_model_comparison.CONFIGS

Initial value:

=  [
    ("impinging/CH4", "configs/canonical/impinging.yaml"),
    ("pintle/Ethanol", "configs/canonical/pintle.yaml"),
]

Definition at line 31 of file thrust_model_comparison.py.

G0

float thrust_model_comparison.G0 = 9.80665

Definition at line 29 of file thrust_model_comparison.py.

PSI

float thrust_model_comparison.PSI = 6894.76

Definition at line 30 of file thrust_model_comparison.py.