TrapezoidalFins Class#

Class that defines and holds information for a trapezoidal fin set.

Geometrical attributes
Fins.n#

Number of fins in fin set.

Type:

int

Fins.rocket_radius#

The reference rocket radius used for lift coefficient normalization, in meters.

Type:

float

Fins.airfoil#

Tuple of two items. First is the airfoil lift curve. Second is the unit of the curve (radians or degrees).

Type:

tuple

Fins.cant_angle#

Fins cant angle with respect to the rocket centerline, in degrees.

Type:

float

Fins.changing_attribute_dict#

Dictionary that stores the name and the values of the attributes that may be changed during a simulation. Useful for control systems.

Type:

dict

Fins.cant_angle_rad#

Fins cant angle with respect to the rocket centerline, in radians.

Type:

float

Fins.root_chord#

Fin root chord in meters.

Type:

float

Fins.tip_chord#

Fin tip chord in meters.

Type:

float

Fins.span#

Fin span in meters.

Type:

float

Fins.name#

Name of fin set.

Type:

string

Fins.sweep_length#

Fins sweep length in meters. By sweep length, understand the axial distance between the fin root leading edge and the fin tip leading edge measured parallel to the rocket centerline.

Type:

float

Fins.sweep_angle#

Fins sweep angle with respect to the rocket centerline. Must be given in degrees.

Type:

float

Fins.d#

Reference diameter of the rocket, in meters.

Type:

float

Fins.ref_area#

Reference area of the rocket, in m².

Type:

float

Fins.Af#

Area of the longitudinal section of each fin in the set.

Type:

float

Fins.AR#

Aspect ratio of each fin in the set

Type:

float

Fins.gamma_c#

Fin mid-chord sweep angle.

Type:

float

Fins.Yma#

Span wise position of the mean aerodynamic chord.

Type:

float

Fins.roll_geometrical_constant#

Geometrical constant used in roll calculations.

Type:

float

Fins.tau#

Geometrical relation used to simplify lift and roll calculations.

Type:

float

Fins.lift_interference_factor#

Factor of Fin-Body interference in the lift coefficient.

Type:

float

Fins.cp#

Tuple with the x, y and z local coordinates of the fin set center of pressure. Has units of length and is given in meters.

Type:

tuple

Fins.cpx#

Fin set local center of pressure x coordinate. Has units of length and is given in meters.

Type:

float

Fins.cpy#

Fin set local center of pressure y coordinate. Has units of length and is given in meters.

Type:

float

Fins.cpz#

Fin set local center of pressure z coordinate. Has units of length and is given in meters.

Type:

float

Fins.cl#

Function which defines the lift coefficient as a function of the angle of attack and the Mach number. Takes as input the angle of attack in radians and the Mach number. Returns the lift coefficient.

Type:

Function

Fins.clalpha#

Lift coefficient slope. Has units of 1/rad.

Type:

float