airfoil module

Classes for generation of airfoil parametrically.

Revision:

1.0.0 $Date: 27/01/2023 09:33$

History:

1.0.0 - Initial Class Creation

Todo

Add method from

Salunke, N. P. & Juned Ahamad, R. A. Airfoil parameterization techniques: A review. American (2014)

class airfoil.AIRFOIL(xu=array([0.0]), yu=array([0.0]), xl=array([0.0]), yl=array([0.0]), name='myfoil')[source]

Bases: object

Class for reading, writing, plotting airfoil files.

Examples:

Example of modle generation

>>> myfoil = AIRFOIL()
>>> myfoil.read('database/rae2822.dat', 'Selig')
>>> airfoil.export('png')

__init__(xu=array([0.0]), yu=array([0.0]), xl=array([0.0]), yl=array([0.0]), name='myfoil')[source]

AIRFOIL Class Initialization.

Parameters

xu (ndarray) – horizontal coordinate on upper surface
yu (ndarray) – vertical coordinate on upper surface
xl (ndarray) – horizontal coordinate on lower surface
yl (ndarray) – vertical coordinate on lower surface
name (string) – name of airfoil

Returns

None

Documentation last updated: Jan. 27, 2023 - Shugo Date

read(f, format)[source]

read airfoil from file.

Parameters

f (string) – path to the file
format (string) – format of airfoil file

Returns

None

Documentation last updated: Jan. 27, 2023 - Shugo Date

show(camber=False)[source]

Parameters

n (int) – number of points
camber (bool) – True -> show camber

Returns

functino on upper surface ll (function?): functino on lower surface

Return type

lu (function?)

Documentation last updated: Jan. 27, 2023 - Shugo Date

savefig(ext, camber=False)[source]

save figure

Parameters

ext (string) – extension of file (pdf, png, …)
camber (bool) – True -> show camber

Returns

function on upper surface ll (function?): function on lower surface

Return type

lu (function?)

Output files:

‘“airfoil_name”.png’ (binary): figure

Documentation last updated: Jan. 27, 2023 - Shugo Date

_get_line()[source]

get cubic spline curve of airfoil

Parameters: None –
Returns: functino on upper surface ll (function?): functino on lower surface
Return type: lu (function?)

Documentation last updated: Jan. 27, 2023 - Shugo Date

_setlayout(ymin, ymax)[source]

get layouted fig and ax

Parameters

ymin (float) – lower limit of y
ymax (float) – upper limit of y

Returns

layouted figure ax (axes): layouted axes

Return type

fig (plt.figure)

Documentation last updated: Jan. 27, 2023 - Shugo Date

savetxt(path, format, ext)[source]

export airfoil file

Parameters

path (string) – path to the output directory
format (string) – format of file (selig, xml, …)
ext (string) – extension of file (dat, txt, …)

Returns

None

Output files:

‘“name”.”ext”’ (ASCII): airfoil file

Documentation last updated: Jan. 27, 2023 - Shugo Date

class airfoil.CST(mu=4, ml=4, beta_u=[0.1277, 0.1399, 0.1903, 0.1927, 0.2019], beta_l=[-0.1299, -0.1345, -0.2247, -0.0783, 0.0412])[source]

Bases: AIRFOIL

Class for airfoils by CST method. Examples:

Example of modle generation

>>> airfoil = CST()
>>> airfoil.generate_airfoil(65)
>>> airfoil.savefig('png', camber=True)
>>> airfoil.show(camber=True)
>>> airfoil.savetxt('selig', 'dat')

Author:

Ryosuke Kano

Shugo Date

__init__(mu=4, ml=4, beta_u=[0.1277, 0.1399, 0.1903, 0.1927, 0.2019], beta_l=[-0.1299, -0.1345, -0.2247, -0.0783, 0.0412])[source]

CST Class Initialization.

Parameters

mu (int) – polynomial degree on upper surface
ml (int) – polynomial degree on lower surface
beta_u (ndarray) – coefficients of Bernstein polynomial on upper surface
beta_l (ndarray) – coefficients of Bernstein polynomial on lower surface

Returns

None

Documentation last updated: Jan. 27, 2023 - Shugo Date

read_coef_from_csv(file)[source]

read coefficient of Bernstein polynomial from csv file

Parameters: file (string) – file name of csv
Returns: None

Documentation last updated: Jan. 27, 2023 - Shugo Date

cst_curve(m, beta, x)[source]

generate airfoil

Parameters

m (int) – polynomial degree
beta (array) – coefficients of Bernstein polynomial
x (ndarray) – chord wise coordinates

Returns

vertical coordinates

Return type

y (ndarray)

Documentation last updated: Jan. 27, 2023 - Shugo Date

generate_airfoil(n)[source]

generate airfoil

Parameters: n (int) – nubmer of point
Returns: None

Documentation last updated: Jan. 27, 2023 - Shugo Date

class airfoil.NACA4(digits='0012')[source]

Bases: AIRFOIL

Class for NSCA 4-digit airfoils.

Examples:

Example of modle generation

>>> airfoil = NACA4()
>>> airfoil.generate_airfoil(65)
>>> airfoil.savefig('png', camber=True)
>>> airfoil.show(camber=True)
>>> airfoil.savetxt('selig', 'dat')

__init__(digits='0012')[source]

NACA4 Class Initialization.

Parameters: digits (string) – 4-digits to generate airfoil

1st digit: max. camber (%) 2nd digit: max. camber position (%) * 10 3-4th digit: max. wing thickness ratio (%)

Returns: None

Documentation last updated: Jan. 27, 2023 - Shugo Date

generate_airfoil(n)[source]

generate airfoil

Parameters: n (int) – nubmer of point
Returns: None

Documentation last updated: Jan. 27, 2023 - Shugo Date

y_camb1(x)[source]

calc camber before max camber

Parameters: x (float) – chordwise coordinate
Returns: vertical coordinate of camber
Return type: y (float)

Documentation last updated: Jan. 27, 2023 - Shugo Date

y_camb2(x)[source]

calc camber after max camber

Parameters: x (float) – chordwise coordinate
Returns: vertical coordinate of camber
Return type: y (float)

Documentation last updated: Jan. 27, 2023 - Shugo Date

calc_thick(x)[source]

calc thickness distribution

Parameters: x (float) – chordwise coordinate
Returns: thickness distribution
Return type: y (float)

Documentation last updated: Jan. 27, 2023 - Shugo Date