engine.pipeline.physics_based_replacements Namespace Reference

Functions
float	calculate_recirculation_length_physics (float D_chamber, float d_pintle_tip, float fuel_velocity, float lox_velocity, float Re_chamber)
float	calculate_evaporation_factor_physics (float evaporation_length, float chamber_length, float SMD, float target_smd, float Pc, float Tc)
float	calculate_smd_factor_physics (float SMD, float target_smd, float Re_injector, float We_injector)
float	calculate_throat_heat_flux_physics (float heat_flux_chamber, float Pc, float V_chamber, float V_throat, float gamma, float D_chamber, float D_throat)
float	calculate_turbulence_enhancement_physics (float Re_throat, float velocity_ratio, float D_chamber, float D_throat)
float	calculate_graphite_thickness_multiplier_physics (float heat_flux_local, float heat_flux_avg, float thermal_conductivity, float backface_temp_limit, float surface_temp)

Detailed Description

Physics-based replacements for arbitrary multipliers.

This module provides physics-based calculations to replace arbitrary factors
and multipliers throughout the codebase.

Function Documentation

calculate_evaporation_factor_physics()

float engine.pipeline.physics_based_replacements.calculate_evaporation_factor_physics	(	float	evaporation_length,
		float	chamber_length,
		float	SMD,
		float	target_smd,
		float	Pc,
		float	Tc )

Calculate evaporation factor based on physics.

Physics:
- If evaporation_length < chamber_length: good evaporation
- Factor based on d^2-law evaporation: t_evap ~ d^2 / K
- Accounts for incomplete evaporation when L_evap > L_chamber

Parameters:
-----------
evaporation_length : float
    Evaporation length [m]
chamber_length : float
    Chamber length [m]
SMD : float
    Sauter mean diameter [m]
target_smd : float
    Target SMD [m]
Pc : float
    Chamber pressure [Pa]
Tc : float
    Chamber temperature [K]

Returns:
--------
evap_factor : float
    Evaporation factor (0-1, higher = better)

Definition at line 66 of file physics_based_replacements.py.

calculate_graphite_thickness_multiplier_physics()

float engine.pipeline.physics_based_replacements.calculate_graphite_thickness_multiplier_physics	(	float	heat_flux_local,
		float	heat_flux_avg,
		float	thermal_conductivity,
		float	backface_temp_limit,
		float	surface_temp )

Calculate graphite thickness multiplier based on thermal requirements.

Physics:
- Thickness needed to maintain backface temperature
- t ~ k × (T_surface - T_backface) / q
- Higher heat flux → thicker graphite needed

Parameters:
-----------
heat_flux_local : float
    Local heat flux [W/m²]
heat_flux_avg : float
    Average heat flux [W/m²]
thermal_conductivity : float
    Graphite thermal conductivity [W/(m·K)]
backface_temp_limit : float
    Maximum backface temperature [K]
surface_temp : float
    Surface temperature [K]

Returns:
--------
multiplier : float
    Thickness multiplier (relative to average)

Definition at line 289 of file physics_based_replacements.py.

calculate_recirculation_length_physics()

float engine.pipeline.physics_based_replacements.calculate_recirculation_length_physics	(	float	D_chamber,
		float	d_pintle_tip,
		float	fuel_velocity,
		float	lox_velocity,
		float	Re_chamber )

Calculate recirculation length based on physics.

Physics:
- Recirculation length scales with chamber diameter
- Depends on Reynolds number (turbulent flow)
- Depends on velocity ratio (fuel/LOX)
- Typical: L_recirc = 0.2-0.4 * D_chamber for turbulent jets

Parameters:
-----------
D_chamber : float
    Chamber diameter [m]
d_pintle_tip : float
    Pintle tip diameter [m]
fuel_velocity : float
    Fuel injection velocity [m/s]
lox_velocity : float
    LOX injection velocity [m/s]
Re_chamber : float
    Chamber Reynolds number

Returns:
--------
L_recirc : float
    Recirculation length [m]

Definition at line 13 of file physics_based_replacements.py.

References max.

calculate_smd_factor_physics()

float engine.pipeline.physics_based_replacements.calculate_smd_factor_physics	(	float	SMD,
		float	target_smd,
		float	Re_injector,
		float	We_injector )

Calculate SMD factor based on physics.

Physics:
- Smaller droplets → better mixing
- Factor based on mixing time: t_mix ~ d^2 / D
- Accounts for spray quality from Weber/Reynolds numbers

Parameters:
-----------
SMD : float
    Actual Sauter mean diameter [m]
target_smd : float
    Target SMD [m]
Re_injector : float
    Injector Reynolds number
We_injector : float
    Injector Weber number

Returns:
--------
smd_factor : float
    SMD factor (0-1, higher = better mixing)

Definition at line 128 of file physics_based_replacements.py.

References max.

calculate_throat_heat_flux_physics()

float engine.pipeline.physics_based_replacements.calculate_throat_heat_flux_physics	(	float	heat_flux_chamber,
		float	Pc,
		float	V_chamber,
		float	V_throat,
		float	gamma,
		float	D_chamber,
		float	D_throat )

Calculate throat heat flux using Bartz correlation (physics-based).

Physics:
- Bartz correlation: q_throat / q_chamber = f(V, P, D)
- Accounts for velocity, pressure, and diameter effects
- No arbitrary multipliers

Parameters:
-----------
heat_flux_chamber : float
    Chamber heat flux [W/m²]
Pc : float
    Chamber pressure [Pa]
V_chamber : float
    Chamber velocity [m/s]
V_throat : float
    Throat velocity [m/s] (sonic)
gamma : float
    Specific heat ratio
D_chamber : float
    Chamber diameter [m]
D_throat : float
    Throat diameter [m]

Returns:
--------
heat_flux_throat : float
    Throat heat flux [W/m²]

Definition at line 176 of file physics_based_replacements.py.

calculate_turbulence_enhancement_physics()

float engine.pipeline.physics_based_replacements.calculate_turbulence_enhancement_physics	(	float	Re_throat,
		float	velocity_ratio,
		float	D_chamber,
		float	D_throat )

Calculate turbulence enhancement at throat based on physics.

Physics:
- Turbulence increases near throat due to:
  1. Higher Reynolds number (sonic conditions)
  2. Flow acceleration (velocity gradient)
  3. Geometry change (diameter reduction)

Parameters:
-----------
Re_throat : float
    Throat Reynolds number
velocity_ratio : float
    V_throat / V_chamber
D_chamber : float
    Chamber diameter [m]
D_throat : float
    Throat diameter [m]

Returns:
--------
enhancement : float
    Turbulence enhancement factor

Definition at line 242 of file physics_based_replacements.py.

References max.