Classes
class	CEACache
class	CEAAuxTables

Functions
bool	_cea_build_allowed ()
float	_isentropic_cf_vac (float gamma, float eps)
float	_scalar_clamp (float x, float lo, float hi)
	_get_CEA_Obj ()
	safe_print (args, *kwargs)
Tuple[float, float, float, float, float, float]	parse_cea_basic (str out)
List[Tuple[int, int, int, float, float, float, float, float, float]]	_compute_cea_point_chunk (List[Tuple[int, int, int, float, float, float]] chunk, str ox_name, str fuel_name, Optional[float] expansion_ratio=None, Optional[Any] lock=None)
Dict[str, np.ndarray]	_load_npz_tables (str path)
Tuple[int, float, bool]	_aux_axis (np.ndarray grid, float x, bool log)
np.ndarray	_fill_nan_nearest (np.ndarray a)
CEAAuxTables	get_aux_tables (str ox_name, str fuel_name)

Variables
int	CEA_TABLE_SCHEMA_VERSION = 2
	_CEA_Obj = None
	logger = logging.getLogger("evaluate")
	_original_print = print
	print = safe_print
	encoding
	errors
	stdout
	buffer
dict	_NPZ_TABLE_MEMO = {}
int	CEA_AUX_SCHEMA_VERSION = 1
tuple	AUX_SPECIES = ("H2O", "CO2", "CO", "H2", "OH", "O2", "O", "H")
	_AUX_MR = np.round(np.linspace(0.8, 4.0, 65), 6)
	_AUX_PC = np.geomspace(1.0e5, 1.2e7, 16)
	_AUX_EPS = np.geomspace(1.1, 60.0, 48)
float	_PSI = 6894.757293168361
float	_BTU_LBM_R = 4186.8
float	_MILLIPOISE = 1.0e-4
float	_MCAL_CM_S_K = 0.4184
dict	_AUX_MEMO = {}

Detailed Description

RocketCEA wrapper with MR/Pc caching and bilinear interpolation

Function Documentation

◆ _aux_axis()

Tuple[int, float, bool] engine.pipeline.cea_cache._aux_axis	(	np.ndarray	grid,
		float	x,
		bool	log )

protected

Cell index, weight and clamp flag on a uniform (or log-uniform) grid.

Definition at line 1130 of file cea_cache.py.

References max, and min.

Referenced by engine.pipeline.cea_cache.CEAAuxTables._bilinear(), and engine.pipeline.cea_cache.CEAAuxTables._exit().

◆ _cea_build_allowed()

bool engine.pipeline.cea_cache._cea_build_allowed ( )

protected

Definition at line 31 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache._build_cache().

◆ _compute_cea_point_chunk()

List[Tuple[int, int, int, float, float, float, float, float, float]] engine.pipeline.cea_cache._compute_cea_point_chunk	(	List[Tuple[int, int, int, float, float, float]]	chunk,
		str	ox_name,
		str	fuel_name,
		Optional[float]	expansion_ratio = None,
		Optional[Any]	lock = None )

protected

Worker function for parallel CEA cache building.

Computes CEA properties for a chunk of grid points.
This function must be at module level for multiprocessing.

Parameters:
-----------
chunk : List[Tuple[int, int, int, float, float, float]]
    List of (i, j, k_idx, Pc_psia, MR, eps) tuples
ox_name : str
    Oxidizer name
fuel_name : str
    Fuel name
expansion_ratio : float, optional
    Fixed expansion ratio (for 2D cache). If None, uses eps from chunk (3D cache)
lock : multiprocessing.Lock, optional
    Lock to serialize RocketCEA calls (RocketCEA is not process-safe)

Returns:
--------
results : List[Tuple[int, int, int, float, float, float, float, float, float]]
    List of (i, j, k_idx, cstar, Cf, Tc, gamma, R, M) tuples

Definition at line 214 of file cea_cache.py.

References _get_CEA_Obj(), and parse_cea_basic().

◆ _fill_nan_nearest()

np.ndarray engine.pipeline.cea_cache._fill_nan_nearest ( np.ndarray a )

protected

Fill failed CEA points from the nearest good one along the first axis (MR), then Pc.

Definition at line 1142 of file cea_cache.py.

References min.

Referenced by engine.pipeline.cea_cache.CEAAuxTables._build().

◆ _get_CEA_Obj()

engine.pipeline.cea_cache._get_CEA_Obj ( )

protected

Lazy import of CEA_Obj - only import when needed for cache building.

Definition at line 101 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEAAuxTables._build(), engine.pipeline.cea_cache.CEACache._build_cache_sequential(), and _compute_cea_point_chunk().

◆ _isentropic_cf_vac()

float engine.pipeline.cea_cache._isentropic_cf_vac	(	float	gamma,
		float	eps )

protected

Ideal vacuum thrust coefficient from gamma + area ratio (isentropic, frozen).

Fallback for caches built before the Cf_vac table existed. Slightly low vs CEA's
shifting-equilibrium Cf_vac (the same ~2% frozen gap documented in the thrust-model
analysis); regenerate the cache to get the exact CEA value. Self-contained to avoid
importing the nozzle solvers here.

Definition at line 49 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache.eval(), and engine.pipeline.cea_cache.CEACache.eval_cf_vac().

◆ _load_npz_tables()

Dict[str, np.ndarray] engine.pipeline.cea_cache._load_npz_tables ( str path )

protected

Return the fully-materialised contents of a cache .npz, memoised per file version.

Definition at line 305 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEAAuxTables._load(), and engine.pipeline.cea_cache.CEACache._load_cache().

◆ _scalar_clamp()

float engine.pipeline.cea_cache._scalar_clamp	(	float	x,
		float	lo,
		float	hi )

protected

float(np.clip(x, lo, hi)) for a scalar, without numpy's per-call overhead.
Matches np.clip exactly, including NaN pass-through (NaN < lo and NaN > hi are
both False, so NaN is returned). Hot path: called per CEA lookup.

Definition at line 85 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache.eval(), and engine.pipeline.cea_cache.CEACache.eval_cf_vac().

◆ get_aux_tables()

CEAAuxTables engine.pipeline.cea_cache.get_aux_tables	(	str	ox_name,
		str	fuel_name )

Definition at line 1301 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache.aux().

◆ parse_cea_basic()

Tuple[float, float, float, float, float, float] engine.pipeline.cea_cache.parse_cea_basic ( str out )

Extract Tc, gamma, R, c*, and Isp from NASA CEA text output (chamber values only).

Returns:
--------
Tc : float [K]
gamma : float
R : float [J/(kg*K)]
cstar : float [m/s]
M : float [kg/kmol]
Isp : float [s] (ambient Isp, or NaN if not found)

Definition at line 162 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache._build_cache_sequential(), and _compute_cea_point_chunk().

◆ safe_print()

engine.pipeline.cea_cache.safe_print	(	*	args,
		**	kwargs )

Log function that handles Unicode encoding errors gracefully

Definition at line 121 of file cea_cache.py.

References decode().

Variable Documentation

◆ _AUX_EPS

engine.pipeline.cea_cache._AUX_EPS = np.geomspace(1.1, 60.0, 48)

protected

Definition at line 1122 of file cea_cache.py.

◆ _AUX_MEMO

dict engine.pipeline.cea_cache._AUX_MEMO = {}

protected

Definition at line 1127 of file cea_cache.py.

◆ _AUX_MR

engine.pipeline.cea_cache._AUX_MR = np.round(np.linspace(0.8, 4.0, 65), 6)

protected

Definition at line 1120 of file cea_cache.py.

◆ _AUX_PC

engine.pipeline.cea_cache._AUX_PC = np.geomspace(1.0e5, 1.2e7, 16)

protected

Definition at line 1121 of file cea_cache.py.

◆ _BTU_LBM_R

float engine.pipeline.cea_cache._BTU_LBM_R = 4186.8

protected

Definition at line 1124 of file cea_cache.py.

◆ _CEA_Obj

engine.pipeline.cea_cache._CEA_Obj = None

protected

Definition at line 99 of file cea_cache.py.

◆ _MCAL_CM_S_K

float engine.pipeline.cea_cache._MCAL_CM_S_K = 0.4184

protected

Definition at line 1126 of file cea_cache.py.

◆ _MILLIPOISE

float engine.pipeline.cea_cache._MILLIPOISE = 1.0e-4

protected

Definition at line 1125 of file cea_cache.py.

◆ _NPZ_TABLE_MEMO

dict engine.pipeline.cea_cache._NPZ_TABLE_MEMO = {}

protected

Definition at line 302 of file cea_cache.py.

◆ _original_print

engine.pipeline.cea_cache._original_print = print

protected

Definition at line 120 of file cea_cache.py.

◆ _PSI

float engine.pipeline.cea_cache._PSI = 6894.757293168361

protected

Definition at line 1123 of file cea_cache.py.

◆ AUX_SPECIES

tuple engine.pipeline.cea_cache.AUX_SPECIES = ("H2O", "CO2", "CO", "H2", "OH", "O2", "O", "H")

Definition at line 1119 of file cea_cache.py.

◆ buffer

engine.pipeline.cea_cache.buffer

Definition at line 157 of file cea_cache.py.

◆ CEA_AUX_SCHEMA_VERSION

int engine.pipeline.cea_cache.CEA_AUX_SCHEMA_VERSION = 1

Definition at line 1118 of file cea_cache.py.

◆ CEA_TABLE_SCHEMA_VERSION

int engine.pipeline.cea_cache.CEA_TABLE_SCHEMA_VERSION = 2

Definition at line 46 of file cea_cache.py.

◆ encoding

engine.pipeline.cea_cache.encoding

Definition at line 154 of file cea_cache.py.

◆ errors

engine.pipeline.cea_cache.errors

Definition at line 154 of file cea_cache.py.

◆ logger

engine.pipeline.cea_cache.logger = logging.getLogger("evaluate")

Definition at line 117 of file cea_cache.py.

◆ print

engine.pipeline.cea_cache.print = safe_print

Definition at line 149 of file cea_cache.py.

Referenced by engine.pipeline.cea_cache.CEACache._build_cache(), engine.pipeline.cea_cache.CEACache._build_cache_parallel(), engine.pipeline.cea_cache.CEACache._build_cache_sequential(), engine.pipeline.cea_cache.CEACache._load_cache(), and engine.pipeline.cea_cache.CEACache.eval().

◆ stdout

engine.pipeline.cea_cache.stdout

Definition at line 157 of file cea_cache.py.

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ _aux_axis()

◆ _cea_build_allowed()

◆ _compute_cea_point_chunk()

◆ _fill_nan_nearest()

◆ _get_CEA_Obj()

◆ _isentropic_cf_vac()

◆ _load_npz_tables()

◆ _scalar_clamp()

◆ get_aux_tables()

◆ parse_cea_basic()

◆ safe_print()

Variable Documentation

◆ _AUX_EPS

◆ _AUX_MEMO

◆ _AUX_MR

◆ _AUX_PC

◆ _BTU_LBM_R

◆ _CEA_Obj

◆ _MCAL_CM_S_K

◆ _MILLIPOISE

◆ _NPZ_TABLE_MEMO

◆ _original_print

◆ _PSI

◆ AUX_SPECIES

◆ buffer

◆ CEA_AUX_SCHEMA_VERSION

◆ CEA_TABLE_SCHEMA_VERSION

◆ encoding

◆ errors

◆ logger

◆ print

◆ stdout