def test_max_thickness(ta_u,
ta_l,
tb_u,
tb_l,
alpha_b,
alpha_c,
expected_value,
tolerance=1e-4):
r"""Test the max_thickness() function of the NURBS foil generator
Parameters
----------
...
expected_value : float
The expected value from max_thickness()
tolerance : float (optional, default is 1e-4)
The tolerance for the value calculation
"""
k = {'ta_u': ta_u,
'ta_l': ta_l,
'tb_u': tb_u,
'tb_l': tb_l,
'alpha_b': alpha_b,
'alpha_c': alpha_c}
section = NURBS(k)
assert expected_value - tolerance <= section.max_thickness() <= expected_value + tolerance
def nurbs_example():
r"""Runs an example'''"""
k = dict()
# sample coefficients: Coefficients for generating NACA5410
k['ta_u'] = 0.15
k['ta_l'] = 0.09
k['tb_u'] = 2.9
k['tb_l'] = 2.9
k['alpha_b'] = 6
k['alpha_c'] = -1.
nurbs_foil = NURBS(k)
print(nurbs_foil)
print(nurbs_foil.get_coords_plain())
nurbs_foil.plot_foil(title="NURBS")
def test_is_symmetrical(ta_u,
ta_l,
tb_u,
tb_l,
alpha_b,
alpha_c,
is_symmetrical_value):
r"""Test the is_symmetrical() function of the NURBS foil generator
Parameters
----------
ta_u
ta_l
tb_u
tb_l
alpha_b
alpha_c
is_symmetrical_value : bool
The expected value from is_symmetrical()
"""
k = {'ta_u': ta_u,
'ta_l': ta_l,
'tb_u': tb_u,
'tb_l': tb_l,
'alpha_b': alpha_b,
'alpha_c': alpha_c}
assert NURBS(k).is_symmetrical() is is_symmetrical_value
def test_is_valid(ta_u, ta_l, tb_u, tb_l, alpha_b, alpha_c, is_valid_value):
r"""Test the is_valid() function of the NURBS foil generator
Parameters
----------
...
is_valid_value : bool
The expected value from is_valid()
"""
k = {'ta_u': ta_u,
'ta_l': ta_l,
'tb_u': tb_u,
'tb_l': tb_l,
'alpha_b': alpha_b,
'alpha_c': alpha_c}
section = NURBS(k)
assert section.is_valid() is is_valid_value
def test_area(ta_u, ta_l, tb_u, tb_l, alpha_b, alpha_c):
r"""Test the area() function of the NURBS generator"""
k = {'ta_u': ta_u,
'ta_l': ta_l,
'tb_u': tb_u,
'tb_l': tb_l,
'alpha_b': alpha_b,
'alpha_c': alpha_c}
assert NURBS(k).area() > 0.0
def test_wrong_constructor_values(ta_u, ta_l, tb_u, tb_l, alpha_b, alpha_c):
r"""Test instantiation with wrong parameters"""
k = {'ta_u': ta_u,
'ta_l': ta_l,
'tb_u': tb_u,
'tb_l': tb_l,
'alpha_b': alpha_b,
'alpha_c': alpha_c}
with pytest.raises(ValueError):
NURBS(k)
def nurbs_foil():
with open(join(getcwd(), "global_best_nurbs.data")) as f:
lines = f.readlines()
ta = float(lines[3])
tb = float(lines[4])
alpha = float(lines[5])
k = {
'ta_u': ta,
'ta_l': ta,
'tb_u': tb,
'tb_l': tb,
'alpha_b': 2 * alpha,
'alpha_c': -alpha
}
foil = NURBS(k)
return foil
def nurbs_params_changed(self, change):
r"""The nurbs definition parameters changed
Parameters
----------
change : dict
"""
self.k = {
'ta_u': self.ta_u,
'ta_l': self.ta_l,
'tb_u': self.tb_u,
'tb_l': self.tb_l,
'alpha_b': self.alpha_b,
'alpha_c': self.alpha_c
}
# self.points = NURBS(self.k).get_coords()
# x_l, y_l, x_u, y_u = tuple(NURBS(self.k)._spline())
# print(tuple(NURBS(self.k)._spline()))
# self.points = (y_u, x_u, y_l, x_l)
self.points = NURBS(self.k).get_coords()
self.notify("nurbs_params_changed", change)
def update(self, message, n, i_par, pts, score, foil_parameterization_type):
r"""
Parameters
----------
message : str
Message prefix
n : int
i_par : int
pts : str
String representation of a pso position
score : float
foil_parameterization_type : str
"""
item = self.ultimate_list.InsertStringItem(self.nb_records, message)
if message == "global_best":
self.ultimate_list.SetItemBackgroundColour(item,
wx.Colour(255, 100, 220))
elif message == "particle_best":
self.ultimate_list.SetItemBackgroundColour(item,
wx.Colour(240, 240, 240))
self.ultimate_list.SetStringItem(self.nb_records, 1, str(n))
self.ultimate_list.SetStringItem(self.nb_records, 2, str(i_par))
self.ultimate_list.SetStringItem(self.nb_records, 3, str(pts))
self.ultimate_list.SetStringItem(self.nb_records, 4, str(score))
self.ultimate_list.SetStringItem(self.nb_records, 5, str(1/score))
if foil_parameterization_type == "SYM_PARSEC":
from foilix.foil_generators.parsec import PARSEC
k = dict()
k['rle'] = pts[1]
k['x_pre'] = pts[2]
# Thickness 6%
k['y_pre'] = -pts[0] / 2.0
k['d2ydx2_pre'] = -pts[3]
# Trailing edge angle
k['th_pre'] = pts[4]
# Suction part
k['x_suc'] = k['x_pre']
k['y_suc'] = -k['y_pre']
k['d2ydx2_suc'] = -k['d2ydx2_pre']
k['th_suc'] = -k['th_pre']
# Trailing edge x and y position
k['xte'] = 1.0 # beware of PARSEC generator check
k['yte'] = 0.0
foil = PARSEC(k)
self.ultimate_list.SetStringItem(self.nb_records,
6,
str(foil.max_thickness()))
self.ultimate_list.SetStringItem(self.nb_records,
7,
str(k['x_pre']))
elif foil_parameterization_type == "SYM_NURBS":
from foilix.foil_generators.nurbs import NURBS
ta = pts[0]
tb = pts[1]
alpha = pts[2]
k = {'ta_u': ta,
'ta_l': ta,
'tb_u': tb,
'tb_l': tb,
'alpha_b': 2*alpha,
'alpha_c': -alpha}
foil = NURBS(k)
self.ultimate_list.SetStringItem(self.nb_records,
6,
str(foil.max_thickness()))
# x_l, y_l, x_u, y_u, = foil.get_coords()
_, _, x_u, y_u, = foil.get_coords()
self.ultimate_list.SetStringItem(self.nb_records,
7,
str(x_u[y_u.tolist().index(max(y_u))]))
elif foil_parameterization_type == "NURBS" \
or foil_parameterization_type == "SYM_PARSEC":
raise NotImplementedError
self.nb_records += 1
def example_nurbs_drag():
r"""Example Nurbs foils drag analysis"""
reynolds = 100000
Cl = 0.2
drags = np.zeros((5, 3))
tb_u = np.linspace(1.8, 2.2, 6)
alpha_b = np.linspace(11.1, 12, 4)
for i in range(1, 6):
for j in range(1, 4):
# make new airfoil
k = dict()
k['ta_u'] = 0.1584
k['ta_l'] = 0.1565
k['tb_u'] = tb_u[i]
k['tb_l'] = 1.8255
k['alpha_b'] = alpha_b[j]
k['alpha_c'] = 3.8270
nurbs_foil = NURBS(k)
# make unique filename
temp_af_filename = "temp_airfoil_{}{}.dat".format(i, j)
# Save coordinates
with open(temp_af_filename, 'w') as nurbs_foil_file:
nurbs_foil_file.write(nurbs_foil.get_coords_plain())
# Let Xfoil do its thing
polar = oper_visc_cl(temp_af_filename, Cl, reynolds, iterlim=1000)
# Save Cd
try:
drags[i - 1][j - 1] = polar[0][0][2]
except IndexError:
raise Warning("Shit! XFOIL didn't converge on NACA{}{}15 at "
"Cl={}.".format(i, j, Cl))
yu, xu, yl, xl, = nurbs_foil.get_coords()
def translated_plt(x, y, *args):
r"""Translated plot
Parameters
----------
x
y
"""
plt.plot(x * 0.8 + (j - .9), y * 0.8 + (i - 0.5), *args)
translated_plt(yl, xl, 'w')
translated_plt(yu, xu, 'w')
os.remove(temp_af_filename)
print(drags)
plt.pcolor(drags, cmap=plt.cm.RdBu)
plt.pcolor(drags, cmap=plt.cm.coolwarm)
cbar = plt.colorbar()
cbar.ax.set_ylabel("Drag coefficient $C_d$")
plt.yticks((.5, 1.5, 2.5, 3.5, 4.5), ("1", "2", "3", "4", "5"))
plt.xticks((.5, 1.5, 2.5), ("1", "2", "3"))
plt.tight_layout()
plt.show()