_BaseFin Class

class rocketpy.rocket.aero_surface.fins._base_fin._BaseFin

Base class for fins, shared by both Fin and Fins classes. Inherits from AeroSurface.

Handles shared initialization logic and common properties.

__init__(name, rocket_radius, root_chord, span, airfoil=None, cant_angle=0)

Initialize the base fin class.

Parameters:

• name (str) – Name of the fin or fin set.

• rocket_radius (float) – Rocket radius in meters.

• root_chord (float) – Root chord of the fin in meters.

• span (float) – Span of the fin in meters.

• airfoil (tuple, optional) – Tuple containing airfoil data and unit (‘degrees’ or ‘radians’).

• cant_angle (float, optional) – Cant angle in degrees.

_update_reference_quantities()

Update quantities that depend on rocket radius.

_update_geometry_chain()

Update geometry-dependent quantities in dependency order.

property rocket_radius

Rocket radius in meters.

Returns:

Rocket radius in meters.

Return type:

float

property rocket_diameter

Reference rocket diameter in meters.

property diameter

Backward-compatible alias for rocket_diameter.

property d

Backward-compatible alias for rocket_diameter.

property ref_area

Backward-compatible alias for reference_area.

property root_chord

Root chord length in meters.

Returns:

Root chord length in meters.

Return type:

float

property span

Fin span in meters.

Returns:

Fin span in meters.

Return type:

float

property cant_angle

Cant angle in degrees.

Returns:

Cant angle in degrees.

Return type:

float

property cant_angle_rad

Cant angle in radians.

Returns:

Cant angle in radians.

Return type:

float

property airfoil

Airfoil data for the fin.

Returns:

Tuple containing airfoil data and unit (‘degrees’ or ‘radians’), or None if using planar fin.

Return type:

tuple or None

info()

Print fin geometry and lift information.

all_info()

Print all available fin information and show all fin plots.

evaluate_single_fin_lift_coefficient()

Evaluate the lift coefficient derivative for a single fin.

Computes the lift coefficient derivative (clalpha) considering the fin’s geometry, airfoil characteristics (if provided), and Mach number effects using Prandtl-Glauert compressibility correction and Diederich’s planform correlation.

Sets the clalpha_single_fin attribute as a Function of Mach number.

abstract evaluate_lift_coefficient()

Evaluate the lift coefficient for the fin.

abstract evaluate_roll_parameters()

Evaluate roll-related parameters for the fin.

abstract evaluate_center_of_pressure()

Evaluate the center of pressure for the fin.

evaluate_geometrical_parameters()

Evaluate geometric parameters of the fin.

This method delegates to the configured geometry strategy.

evaluate_shape()

Evaluate the shape representation of the fin.

This method delegates to the configured geometry strategy.

abstract draw()

Draw or render the fin.