def test_extrap1_w_airfoil(self):
cdmax = 1.29
af = Airfoil([self.polar2])
newaf = af.extrapolate(cdmax=cdmax)
newpolar = newaf.polars[0]
alpha_extrap = [
-180, -170, -160, -150, -140, -130, -120, -110, -100, -90, -80,
-70, -60, -50, -40, -30, -20, -10.1, -8.2, -6.1, -4.1, -2.1, 0.1,
2, 4.1, 6.2, 8.1, 10.2, 11.3, 12.1, 13.2, 14.2, 15.3, 16.3, 17.1,
18.1, 19.1, 20.1, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130,
140, 150, 160, 170, 180
]
cl_extrap = [
0.0000, 0.2299, 0.4597, 0.4907, 0.5053, 0.4805, 0.4102, 0.2985,
0.1565, 0.0000, -0.1565, -0.2985, -0.4102, -0.4805, -0.5053,
-0.4907, -0.4637, -0.6300, -0.5600, -0.6400, -0.4200, -0.2100,
0.0500, 0.3000, 0.5400, 0.7900, 0.9000, 0.9300, 0.9200, 0.9500,
0.9900, 1.0100, 1.0200, 1.0000, 0.9400, 0.8500, 0.7000, 0.6600,
0.7010, 0.7219, 0.6864, 0.5860, 0.4264, 0.2235, 0.0000, -0.1565,
-0.2985, -0.4102, -0.4805, -0.5053, -0.4907, -0.4597, -0.2299,
0.0000
]
cd_extrap = [
0.1770, 0.2132, 0.3173, 0.4758, 0.6686, 0.8708, 1.0560, 1.1996,
1.2818, 1.2900, 1.2818, 1.1996, 1.0560, 0.8708, 0.6686, 0.4758,
0.3158, 0.0390, 0.0233, 0.0131, 0.0134, 0.0119, 0.0122, 0.0116,
0.0144, 0.0146, 0.0162, 0.0274, 0.0303, 0.0369, 0.0509, 0.0648,
0.0776, 0.0917, 0.0994, 0.2306, 0.3142, 0.3186, 0.4758, 0.6686,
0.8708, 1.0560, 1.1996, 1.2818, 1.2900, 1.2818, 1.1996, 1.0560,
0.8708, 0.6686, 0.4758, 0.3173, 0.2132, 0.1770
]
cm_extrap = np.linspace(0, 0, len(cd_extrap))
# re-interpolate b/c angles of attack are different
cl = np.interp(alpha_extrap, newpolar.alpha, newpolar.cl)
cd = np.interp(alpha_extrap, newpolar.alpha, newpolar.cd)
cm = np.interp(alpha_extrap, newpolar.alpha, newpolar.cm)
# test equality
np.testing.assert_allclose(cl, cl_extrap, atol=1.5e-4)
np.testing.assert_allclose(cd, cd_extrap, atol=1.5e-4)
np.testing.assert_allclose(cm, cm_extrap, atol=5e-3)
def test_extrap1_w_airfoil(self):
cdmax = 1.29
af = Airfoil([self.polar])
newaf = af.extrapolate(cdmax=cdmax)
newpolar = newaf.polars[0]
alpha_extrap = [-180, -170, -160, -150, -140, -130, -120, -110, -100,
-90, -80, -70, -60, -50, -40, -30, -20, -10.1, -8.2,
-6.1, -4.1, -2.1, 0.1, 2, 4.1, 6.2, 8.1, 10.2, 11.3,
12.1, 13.2, 14.2, 15.3, 16.3, 17.1, 18.1, 19.1, 20.1,
30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140,
150, 160, 170, 180]
cl_extrap = [0.0000, 0.2299, 0.4597, 0.4907, 0.5053, 0.4805, 0.4102,
0.2985, 0.1565, 0.0000, -0.1565, -0.2985, -0.4102,
-0.4805, -0.5053, -0.4907, -0.4637, -0.6300, -0.5600,
-0.6400, -0.4200, -0.2100, 0.0500, 0.3000, 0.5400,
0.7900, 0.9000, 0.9300, 0.9200, 0.9500, 0.9900, 1.0100,
1.0200, 1.0000, 0.9400, 0.8500, 0.7000, 0.6600, 0.7010,
0.7219, 0.6864, 0.5860, 0.4264, 0.2235, 0.0000, -0.1565,
-0.2985, -0.4102, -0.4805, -0.5053, -0.4907, -0.4597,
-0.2299, 0.0000]
cd_extrap = [0.1770, 0.2132, 0.3173, 0.4758, 0.6686, 0.8708, 1.0560,
1.1996, 1.2818, 1.2900, 1.2818, 1.1996, 1.0560, 0.8708,
0.6686, 0.4758, 0.3158, 0.0390, 0.0233, 0.0131, 0.0134,
0.0119, 0.0122, 0.0116, 0.0144, 0.0146, 0.0162, 0.0274,
0.0303, 0.0369, 0.0509, 0.0648, 0.0776, 0.0917, 0.0994,
0.2306, 0.3142, 0.3186, 0.4758, 0.6686, 0.8708, 1.0560,
1.1996, 1.2818, 1.2900, 1.2818, 1.1996, 1.0560, 0.8708,
0.6686, 0.4758, 0.3173, 0.2132, 0.1770]
# re-interpolate b/c angles of attack are different
cl = np.interp(alpha_extrap, newpolar.alpha, newpolar.cl)
cd = np.interp(alpha_extrap, newpolar.alpha, newpolar.cd)
# test equality
np.testing.assert_allclose(cl, cl_extrap, atol=1.5e-4)
np.testing.assert_allclose(cd, cd_extrap, atol=1.5e-4)
r_over_R,
chord_over_r,
tsr,
alpha_max_corr=alpha_max_corr,
alpha_linear_min=alpha_linear_min,
alpha_linear_max=alpha_linear_max,
)
# 4 ---------
# 5 ---------
cdmax = 1.3
# compute a 3D corrected and extended airfoil
af_extrap1 = af.extrapolate(cdmax)
# a second example using the optional inputs
AR = 17 # blade aspect ratio. If provided, cdmax is estimated using the aspect ratio.
cdmin = 0.001 # minimum drag coefficient. Viterna's method can occasionally produce
# negative drag coefficients. A minimum is used to prevent unphysical data.
# The passed in value is used to override the default.
af_extrap2 = af.extrapolate(cdmax, AR=AR, cdmin=cdmin)
# 5 ---------
# 6 ---------
# create new airfoil that uses the same angles of attack at each Reynolds number
af_common1 = af.interpToCommonAlpha()
af3D_ex2 = af.correction3D(r_over_R,
chord_over_r,
tsr,
alpha_max_corr=alpha_max_corr,
alpha_linear_min=alpha_linear_min,
alpha_linear_max=alpha_linear_max)
# 4 ---------
# 5 ---------
cdmax = 1.3
# compute a 3D corrected and extended airfoil
af_extrap1 = af.extrapolate(cdmax)
# a second example using the optional inputs
AR = 17 # blade aspect ratio. If provided, cdmax is estimated using the aspect ratio.
cdmin = 0.001 # minimum drag coefficient. Viterna's method can occasionally produce
# negative drag coefficients. A minimum is used to prevent unphysical data.
# The passed in value is used to override the default.
af_extrap2 = af.extrapolate(cdmax, AR=AR, cdmin=cdmin)
# 5 ---------
# 6 ---------
# create new airfoil that uses the same angles of attack at each Reynolds number
af_common1 = af.interpToCommonAlpha()
