Airfoil 2D

class pyturbo.aero.airfoil2D.Airfoil2D(alpha1: float, alpha2: float, axial_chord: float, stagger: float, left_to_right: bool = False)

Bases: object

Design a 2D Airfoil using bezier curves

add_le_thickness(thickness: float, counter_rotation: bool = False)

Adds thickness to leading edge either on pressure side or suction side.

If counter rotation is false, thickness is added to the suction side

Parameters:

• thickness (float) – float value for defining a bezier curve thickness

• counter_rotation (bool, optional) – switches the side for the bezier curve initial thickness. Defaults to False.

add_pitch(x_pitch: float)

Adds extra pitch by shifting the turbine blade over by a x direction

Parameters:

x_pitch (float) – amount to shift in the pitch direction

add_ps_thickness(thicknessArray: List[float], expansion_ratio: float = 1.2, camberPercent: float = 0.95, aft_loaded: bool = False)

Add thickness to the pressure side

Parameters:

• thicknessArray (List[float]) – thickness along the pressure side. Example: [0.2400, 0.2000, 0.1600, 0.1400]

• expansion_ratio (float, optional) – determines the spacing of the thickness array from leading edge. Defaults to 1.2.

• camberPercent (float, optional) – Percent camber over which the thickness points are distributed. Defaults to 0.95.

• aft_loaded (bool, optional) – If True, cluster thickness control points near the trailing edge (compressor-style aft-loaded). If False, cluster near the leading edge (turbine-style front-loaded). Defaults to False.

add_ss_flow_guidance(n: int = 8)

This function straightens out the suction side by specifying n bezier control points instead of a straight line.

Parameters:

n (int) – number of control points, increase this to make straightening more aggressive. Defaults to 8.

add_ss_flow_guidance_2(s_c: float, n: int)

Straightens out the suction side. Computes the intersection point of the throat and draws a line, adds bezier points along the line

Parameters:

• s_c (float) – pitch-to-chord ratio

• n (int) – number of bezier control points

add_ss_thickness(thicknessArray: List[float], camberPercent: float = 0.8, expansion_ratio: float = 1.2, aft_loaded: bool = False)

Adds thickness to the suction side by specifying bezier control points

Parameters:

• thicknessArray (List[float]) – thickness along the suction side. Example: [0.2400, 0.2000, 0.1600, 0.1400]

• camberPercent (float, optional) – Percent camber where straightening of the suction side happens. Defaults to 1.

• expansion_ratio (float, optional) – If thickness location is specified then this is not necessary otherwise thickness_loc is calculated by the expansion ratio. Defaults to 1.2.

• aft_loaded (bool, optional) – If True, cluster thickness control points near the trailing edge (compressor-style aft-loaded). If False, cluster near the leading edge (turbine-style front-loaded). Defaults to False.

alpha1: float

alpha2: float

cambBezierX: List[float]

cambBezierY: List[float]

camberBezier: bezier

center_le()

Shifts the airfoil so the leading edge is at (0,0) instead of the trailing edge.

chord: float

custom_camber(x: float, y: float)

Creates a custom bezier curve camberline from 3 points [LEPoint, (x,y), TEPoint]

Usage:

Example profile.custom_camber(0.5,0.5)

Parameters:

• x (float) – arbitrary x coordinate

• y (float) – arbitrary y coordinate

flip()

Swaps the leading edge with trailing edge

flip_cw()

Flips the airfoil from counter-clockwise (CCW) to clockwise (CW) design by mirroring across the X-axis.

get_axial_chord()

returns the axial chord

Returns:

axial_chord

Return type:

float

get_centroid()

Returns the centroid of the airfoil

Returns:

centroid x and y coordinates (x,y)

Return type:

float,float

get_points(n: int = 100) → Tuple[ndarray[tuple[int, ...], dtype[_ScalarType_co]], ndarray[tuple[int, ...], dtype[_ScalarType_co]]]

Returns n points defining the suction side and pressure side.

Parameters:

n (int, optional) – Number of points. Defaults to 100.

Returns:

suction side and pressure side point arrays, each of shape (n, 2)

Return type:

Tuple[npt.NDArray,npt.NDArray]

match_le_thickness()

Matches the leading edge second derivative curvature. Convenience wrapper for match_thickness(‘LE’).

match_thickness(location: str = 'LE')

Matches the second derivative curvature at the leading or trailing edge by adjusting the opposite side thickness.

Parameters:

location (str) – ‘LE’ to match leading edge (default), ‘TE’ to match trailing edge.

Returns:

None

plot2D()

Plots the airfoil.

Returns:

The figure object. Caller can fig.show(),

fig.savefig(...), or pass it to plt.close(fig) when done.

Return type:

matplotlib.figure.Figure

plot2D_channel(pitchChordRatio: float)

plots the 2D airfoil in a channel with another airfoil given a pitch to chord ratio

Parameters:

pitchChordRatio (float) – pitch to chord ratio (spacing between airfoils relative to the chord)

Returns:

matplotlib figure containing the channel plot

Return type:

plt.figure

plot_camber()

Plots the camber of the airfoil.

Returns:

The figure object. Caller can fig.show(),

fig.savefig(...), or pass it to plt.close(fig) when done.

Return type:

matplotlib.figure.Figure

plot_derivative2(xlim=[0, 1], ylim=[-400, 400])

Plots the second derivative of the airfoil.

References

https://mathformeremortals.wordpress.com/2013/01/12/a-numerical-second-derivative-from-three-points/

Parameters:

• xlim (list, optional) – Plot x-axis. Defaults to [0,1].

• ylim (list, optional) – Plot y-axis. Defaults to [-400,400].

psBezier: bezier

psBezierX: List[float]

psBezierY: List[float]

psBezier_pw: pw_bezier2D | None

rotate(angle: float)

Rotates the airfoil around the origin by angle degrees (CCW positive).

Parameters:

angle (float) – rotation angle in degrees

shift(x: float, y: float)

Shifts the blade over by x or y direction. LE points +y where TE is at (0,0) Be sure to take into account the rotation of the blade

Parameters:

• x (float) – amount to shift the blade by in x direction

• y (float) – amount to shift the blade by in y direction

ssBezier: bezier

ssBezierX: List[float]

ssBezierY: List[float]

ssBezier_pw: pw_bezier2D | None

stagger: float

te_create(radius: float, wedge_ss: float, wedge_ps: float)

Creates the trailing edge using a semi-circle

Parameters:

• radius (float) – circle radius

• wedge_ss (float) – wedge angle on the suction side

• wedge_ps (float) – wedge angle on the pressure side

te_create_reversible(thickness: float)

Creates a reversible (rounded/blunt) trailing edge.

Parameters:

thickness (float) – trailing edge thickness as a fraction of chord

thickness()

Calculates the location and value of maximum thickness along with average thickness

Returns:

along camberline of max thickness float: max thickness float: average thickness

Return type:

int

pyturbo.aero.airfoil2D.channel_get(airfoil: Airfoil2D, s_c: float)

Gets adjacent airfoil

Parameters:

• airfoil (Airfoil2D) – airfoil 2D object

• s_c (float) – pitch to chord ratio

Returns:

pitch in between airfoils numpy.ndarray: x coordinate of the suction side numpy.ndarray: x coordinate of the pressure side numpy.ndarray: y coordinate of the suction side numpy.ndarray: y coordinate of the pressure side airfoil2D: the adjacent airfoil

Return type:

List[float]

pyturbo.aero.airfoil2D.plot2D_compare(airfoils: List[Airfoil2D], labels: List[str] | None = None)

Plots multiple 2D airfoils overlaid on the same figure for comparison.

Parameters:

• airfoils (List[Airfoil2D]) – list of Airfoil2D objects to plot

• labels (Optional[List[str]]) – optional labels for each airfoil in the legend