pymead.core.naca4.NACA4#

class NACA4(max_camber: Param, max_camber_loc: Param, max_thickness: Param, leading_edge: Point, trailing_edge: Point, upper: bool, default_nt: int | None = None, name: str | None = None, cosine_spacing: bool = True, sharp_trailing_edge: bool = False, t_start: float | None = None, t_end: float | None = None, **kwargs)[source]#

Bases: ParametricCurve

__init__(max_camber: Param, max_camber_loc: Param, max_thickness: Param, leading_edge: Point, trailing_edge: Point, upper: bool, default_nt: int | None = None, name: str | None = None, cosine_spacing: bool = True, sharp_trailing_edge: bool = False, t_start: float | None = None, t_end: float | None = None, **kwargs)[source]#

Computes the profile for either the lower or upper surface of a NACA 4-series airfoil.

Parameters:

  • point_sequence (PointSequence) – Sequence of points defining the control points for the Bézier curve

  • name (str or None) – Optional name for the curve. Default: None

  • t_start (float or None) – Optional starting parameter vector value for the Bézier curve. Not specifying this value automatically gives a value of 0.0. Default: None

  • t_end (float or None) – Optional ending parameter vector value for the Bézier curve. Not specifying this value automatically gives a value of 1.0. Default: None

Methods

compute_camber(x)

Computes the camber distribution of the NACA 4-series airfoil.

derivative(theta, x, yt, order)

Calculates an arbitrary-order derivative of the Bézier curve

evaluate([t])

Evaluates the curve using an optionally specified parameter vector.

get_4_digit_designation()

get_dict_rep()

Gets a dictionary representation of the pymead object.

point_removal_deletes_curve()

point_sequence()

points()

remove()

remove_point([idx, point])

set_point_sequence(point_sequence)

Attributes

compute_camber(x: ndarray) → ndarray[source]#

Computes the camber distribution of the NACA 4-series airfoil.

Parameters:

x (np.ndarray) – The pre-computed distribution of \(x\)-values

Returns:

Array of the same size as x containing the camber distribution.

Return type:

np.ndarray

derivative(theta: ndarray, x: ndarray, yt: ndarray, order: int) → ndarray[source]#

Calculates an arbitrary-order derivative of the Bézier curve

Parameters:

  • theta (np.ndarray) – The pre-computed camber angle distribution

  • x (np.ndarray) – The pre-computed distribution of \(x\)-values

  • yt (np.ndarray) – The pre-computed thickness distribution

  • order (int) – The order of the derivative. The only valid orders are 1 and 2.

Returns:

An array of shape=(N,2) where N is the number of evaluated points specified by the \(x\) vector. The columns represent \(C^{(m)}_x(t)\) and \(C^{(m)}_y(t)\), where \(m\) is the derivative order.

Return type:

np.ndarray

evaluate(t: array | None = None, **kwargs)[source]#

Evaluates the curve using an optionally specified parameter vector.

Parameters:

t (np.ndarray or None) – Optional direct specification of the parameter vector for the curve. Not specifying this value gives a vector from t_start or t_end with the default size and with spacing determined by the value of cosine_spacing specified in the class constructor. Default: None

Returns:

Data class specifying the following information about the NACA 4-series airfoil curve:

\[C_x(t), C_y(t), C'_x(t), C'_y(t), C''_x(t), C''_y(t), \kappa(t)\]

where the \(x\) and \(y\) subscripts represent the \(x\) and \(y\) components of the vector-valued functions \(\vec{C}(t)\), \(\vec{C}'(t)\), and \(\vec{C}''(t)\).

Return type:

PCurveData

get_dict_rep()[source]#

Gets a dictionary representation of the pymead object. In general, this dictionary should consist of only the required arguments for object instantiation. For example, the dictionary representation of a point looks something like this: {"x": 0.3, "y": 0.5}. If the argument requires a reference to a PymeadObj rather than a string or float value, the name() method should be the value that is stored. For an example, see the overridden value of this method in pymead.core.airfoil.Airfoil. All subclasses of PymeadObj must implement this method, since it is the way pymead objects are stored in saved instances of a GeometryCollection (.jmea files).