NoseCone Class#
- class rocketpy.NoseCone[source]#
Keeps nose cone information.
Note
- Local coordinate system:
the origin at the tip of the nose cone and
the Z axis along the longitudinal axis of symmetry, positive downwards (top -> bottom).
- Variables:
NoseCone.length (
float
) – Nose cone length. Has units of length and must be given in meters.NoseCone.kind (
string
) – Nose cone kind. Can be “conical”, “ogive”, “elliptical”, “tangent”, “von karman”, “parabolic”, “powerseries” or “lvhaack”.NoseCone.bluffness (
float
) – Ratio between the radius of the circle on the tip of the ogive and the radius of the base of the ogive. Currently only used for the nose cone’s drawing. Must be between 0 and 1. Default is None, which means that the nose cone will not have a sphere on the tip. If a value is given, the nose cone’s length will be slightly reduced because of the addition of the sphere. Must be None or 0 if a “powerseries” nose cone kind is specified.NoseCone.rocket_radius (
float
) – The reference rocket radius used for lift coefficient normalization, in meters.NoseCone.base_radius (
float
) – Nose cone base radius. Has units of length and must be given in meters.NoseCone.radius_ratio (
float
) – Ratio between the nose cone base radius and the rocket radius. Has no units. If base radius is not given, the ratio between base radius and rocket radius is assumed as 1, meaning that the nose cone has the same radius as the rocket. If base radius is given, the ratio between base radius and rocket radius is calculated and used for lift calculation.NoseCone.power (
float
) – Factor that controls the bluntness of the shape for a power series nose cone. Must be between 0 and 1. It is ignored when other nose cone types are used.NoseCone.name (
string
) – Nose cone name. Has no impact in simulation, as it is only used to display data in a more organized matter.NoseCone.cp (
tuple
) – Tuple with the x, y and z local coordinates of the nose cone center of pressure. Has units of length and is given in meters.NoseCone.cpx (
float
) – Nose cone local center of pressure x coordinate. Has units of length and is given in meters.NoseCone.cpy (
float
) – Nose cone local center of pressure y coordinate. Has units of length and is given in meters.NoseCone.cpz (
float
) – Nose cone local center of pressure z coordinate. Has units of length and is given in meters.NoseCone.cl (
Function
) – 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.NoseCone.clalpha (
float
) – Lift coefficient slope. Has units of 1/rad.NoseCone.plots (
plots.aero_surface_plots._NoseConePlots
) – This contains all the plots methods. Use help(NoseCone.plots) to know more about it.NoseCone.prints (
prints.aero_surface_prints._NoseConePrints
) – This contains all the prints methods. Use help(NoseCone.prints) to know more about it.
- __init__(length, kind, base_radius=None, bluffness=None, rocket_radius=None, power=None, name='Nose Cone')[source]#
Initializes the nose cone. It is used to define the nose cone length, kind, center of pressure and lift coefficient curve.
- Parameters:
length (
float
) – Nose cone length. Has units of length and must be given in meters.kind (
string
) – Nose cone kind. Can be “conical”, “ogive”, “elliptical”, “tangent”, “von karman”, “parabolic”, “powerseries” or “lvhaack”. If “powerseries” is used, the “power” argument must be assigned to a value between 0 and 1.base_radius (
float
, optional) – Nose cone base radius. Has units of length and must be given in meters. If not given, the ratio betweenbase_radius
androcket_radius
will be assumed as 1.bluffness (
float
, optional) – Ratio between the radius of the circle on the tip of the ogive and the radius of the base of the ogive. Currently only used for the nose cone’s drawing. Must be between 0 and 1. Default is None, which means that the nose cone will not have a sphere on the tip. If a value is given, the nose cone’s length will be reduced to account for the addition of the sphere at the tip. Must be None or 0 if a “powerseries” nose cone kind is specified.rocket_radius (
int
,float
, optional) – The reference rocket radius used for lift coefficient normalization. If not given, the ratio betweenbase_radius
androcket_radius
will be assumed as 1.power (
float
, optional) – Factor that controls the bluntness of the shape for a power series nose cone. Must be between 0 and 1. It is ignored when other nose cone types are used.name (
str
, optional) – Nose cone name. Has no impact in simulation, as it is only used to display data in a more organized matter.
- Return type:
None
- evaluate_geometrical_parameters()[source]#
Calculates and saves nose cone’s radius ratio.
- Return type:
None
- evaluate_nose_shape()[source]#
Calculates and saves nose cone’s shape as lists and re-evaluates the nose cone’s length for a given bluffness ratio. The shape is saved as two vectors, one for the x coordinates and one for the y coordinates.
- Return type:
None
- evaluate_lift_coefficient()[source]#
Calculates and returns nose cone’s lift coefficient. The lift coefficient is saved and returned. This function also calculates and saves its lift coefficient derivative.
- Return type:
None
- evaluate_k()[source]#
Updates the self.k attribute used to compute the center of pressure when using “powerseries” nose cones.
- Return type:
None
- evaluate_center_of_pressure()[source]#
Calculates and returns the center of pressure of the nose cone in local coordinates. The center of pressure position is saved and stored as a tuple. Local coordinate origin is found at the tip of the nose cone.
- Returns:
self.cp – Tuple containing cpx, cpy, cpz.
- Return type:
tuple