|
| bool | enabled = Field(default=False, description="Enable graphite throat insert") |
| float | material_density = Field(default=1800.0, gt=0, description="Graphite BULK density [kg/m³], from the grade's datasheet (isomolded 1750-1900). Not the 2260 of a single crystal: recession is carbon mass flux over this density") |
| float | heat_of_ablation = Field(default=8.0e6, gt=0, description="Effective heat of ablation [J/kg] (graphite: ~8-12 MJ/kg)") |
| float | thermal_conductivity = Field(default=100.0, gt=0, description="Graphite thermal conductivity [W/(m·K)] (typical: 50-150)") |
| float | specific_heat = Field(default=710.0, gt=0, description="Graphite specific heat [J/(kg·K)]; the insert's heat capacity when specific_heat_model is 'constant'") |
| Literal | specific_heat_model |
| Optional | material_source |
| float | initial_thickness = Field(default=0.005, gt=0, description="Initial graphite insert thickness [m]") |
| float | surface_temperature_limit = Field(default=2500.0, gt=0, description="Maximum surface temperature before failure [K]") |
| float | oxidation_temperature = Field(default=800.0, gt=0, description="Onset temperature for oxidation [K]") |
| float | oxidation_rate = Field(default=1e-6, ge=0, description="Unused by the species model (kept so old configs load)") |
| Optional | activation_energy = Field(default=180e3, gt=0, description="Activation energy for Arrhenius oxidation rate [J/mol]. Typical: 150-200 kJ/mol") |
| float | oxidation_reference_temperature = Field(default=1500.0, gt=0, description="Reference temperature where oxidation_rate is defined [K]. Typical: 1500-1800 K") |
| float | oxidation_reference_pressure = Field(default=1.0e6, gt=0, description="Reference pressure where oxidation_rate is defined [Pa]. Typical: 1 MPa") |
| Optional | recession_multiplier = Field(default=None, gt=0, description="Recession multiplier vs chamber (if None, calculated from flow conditions). Typically 1.3-2.5") |
| bool | sizing_only_mode = Field(default=False, description="If True, suppress recession for sizing iterations. Graphite does recede in reality; use only for design phase.") |
| bool | simplified_graphite_oxidation = Field(default=False, description="If True, use the constant `simplified_oxidation_rate` instead of instead of the physics-based model.") |
| float | simplified_oxidation_rate |
| float | sizing_recession_rate |
| float | axial_half_length_ratio |
| Optional | axial_half_length |
| float | char_layer_conductivity = Field(default=5.0, gt=0, description="Thermal conductivity of protective layer [W/(m·K)]") |
| float | char_layer_thickness = Field(default=0.0005, gt=0, description="Thickness of protective layer [m]") |
| float | coverage_fraction = Field(default=1.0, gt=0, le=1.0, description="Fraction of throat/nozzle with graphite insert") |
| Optional | emissivity = Field(default=None, ge=0, le=1, description="Surface emissivity for radiation (default: 0.8)") |
| Optional | ambient_temperature = Field(default=None, gt=0, description="Ambient temperature for radiation [K] (default: 300 K)") |
| Optional | feedback_fraction_min = Field(default=None, ge=0, le=1, description="Minimum oxidation heat feedback fraction (default: 0.0)") |
| Optional | feedback_fraction_max = Field(default=None, ge=0, le=1, description="Maximum oxidation heat feedback fraction (default: 0.2)") |
| Optional | oxidation_enthalpy = Field(default=None, gt=0, description="Unused: reaction enthalpies are per species (graphite_cooling.CARBON_OXIDISERS)") |
| Optional | ablation_surface_temperature = Field(default=None, gt=0, description="Surface temperature at which thermal ablation pins T_s [K] (default: 3000 K). Above this, T_s is fixed and m_dot_th balances energy.") |
| float | ablation_transition_width = Field(default=200.0, gt=0, description="Temperature width [K] for smooth transition to thermal ablation regime.") |
| Optional | oxidation_pressure_exponent = Field(default=None, ge=0, description="Pressure exponent for oxidation kinetics (default: 0.5)") |
| Optional | oxidation_pre_exponential = Field(default=None, gt=0, description="Pre-exponential factor for Arrhenius oxidation (default: calculated from oxidation_rate)") |
| Optional | mixture_mw = Field(default=None, gt=0, description="Average molecular weight of combustion products [kg/mol] (default: 0.024)") |
| Optional | oxidation_stoichiometry_ratio = Field(default=None, gt=0, description="Moles of C per mole of O2 (1.0 for CO2, 2.0 for CO) (default: 1.0)") |
| Optional | oxygen_mass_fraction |
| Optional | oxygen_mole_fraction |
| Optional | friction_coefficient_override = Field(default=None, gt=0, description="Override skin friction coefficient Cf for blowing parameter calculation.") |
| Optional | reference_diffusivity = Field(default=None, gt=0, description="Reference O2 diffusivity [m²/s] at reference temperature and pressure.") |
| float | reference_diffusivity_temperature = Field(default=1500.0, gt=0, description="Reference temperature [K] for oxygen diffusivity scaling.") |
| float | reference_diffusivity_pressure = Field(default=1.0e6, gt=0, description="Reference pressure [Pa] for oxygen diffusivity scaling.") |
| SurfaceReactionConfig | oxidation_H2O |
| SurfaceReactionConfig | oxidation_CO2 |
| SurfaceReactionConfig | oxidation_OH |
Graphite throat insert configuration (separate from chamber ablator)
Definition at line 549 of file config_schemas.py.
1.15.0