def test_stall1_w_airfoil(self):
R = 2.4
r = 0.25*R
chord = 0.18
Omega = 200*pi/30
Uinf = 10.0
tsr = Omega*R/Uinf
af = Airfoil([self.polar])
newaf = af.correction3D(r/R, chord/r, tsr,
alpha_max_corr=30,
alpha_linear_min=-4,
alpha_linear_max=4)
newpolar = newaf.polars[0]
cl_3d = [-0.8466, -0.7523, -0.6420, -0.5342, -0.4302, -0.3284,
-0.2276, -0.1303, -0.0404, 0.0618, 0.2191, 0.3321, 0.4336,
0.5501, 0.6755, 0.7363, 0.8101, 0.8973, 0.9810, 1.0640,
1.1450, 1.2098, 1.2682, 1.3281, 1.3731, 1.3088, 1.3159,
1.3534, 1.4010, 1.4515, 1.9140, 1.8857, 1.6451]
cd_3d = [0.0399, 0.0334, 0.0316, 0.0293, 0.0269, 0.0254, 0.0246,
0.0246, 0.0246, 0.0252, 0.0249, 0.0200, 0.0167, 0.0157,
0.0174, 0.0183, 0.0212, 0.0255, 0.0303, 0.0367, 0.0465,
0.0615, 0.0800, 0.1047, 0.1301, 0.1695, 0.2047, 0.2384,
0.2728, 0.3081, 0.8097, 1.2625, 1.6280]
# test equality
np.testing.assert_allclose(newpolar.cl, cl_3d, atol=1e-3)
np.testing.assert_allclose(newpolar.cd, cd_3d, atol=1e-3)
def test_stall1_w_airfoil(self):
R = 2.4
r = 0.25 * R
chord = 0.18
Omega = 200 * pi / 30
Uinf = 10.0
tsr = Omega * R / Uinf
af = Airfoil([self.polar])
newaf = af.correction3D(r / R,
chord / r,
tsr,
alpha_max_corr=30,
alpha_linear_min=-4,
alpha_linear_max=4)
_, _, cl_grid, cd_grid, cm_grid = newaf.createDataGrid()
newpolar = newaf.polars[0]
cl_3d = [
-0.8466, -0.7523, -0.6420, -0.5342, -0.4302, -0.3284, -0.2276,
-0.1303, -0.0404, 0.0618, 0.2191, 0.3321, 0.4336, 0.5501, 0.6755,
0.7363, 0.8101, 0.8973, 0.9810, 1.0640, 1.1450, 1.2098, 1.2682,
1.3281, 1.3731, 1.3088, 1.3159, 1.3534, 1.4010, 1.4515, 1.9140,
1.8857, 1.6451
]
cd_3d = [
0.0399, 0.0334, 0.0316, 0.0293, 0.0269, 0.0254, 0.0246, 0.0246,
0.0246, 0.0252, 0.0249, 0.0200, 0.0167, 0.0157, 0.0174, 0.0183,
0.0212, 0.0255, 0.0303, 0.0367, 0.0465, 0.0615, 0.0800, 0.1047,
0.1301, 0.1695, 0.2047, 0.2384, 0.2728, 0.3081, 0.8097, 1.2625,
1.6280
]
cm_test = [[-0.0037], [-0.0044], [-0.0051], [0.0018], [-0.0216],
[-0.0282], [-0.0346], [-0.0405], [-0.0455], [-0.0507],
[-0.0404], [-0.0321], [-0.0281], [-0.0284], [-0.0322],
[-0.0361], [-0.0363], [-0.0393], [-0.0398], [-0.0983],
[-0.1242], [-0.1155], [-0.1068], [-0.0981], [-0.0894],
[-0.0807], [-0.072], [-0.0633], [-0.054], [-0.045],
[-0.036], [-0.22], [-0.13]]
# test equality
np.testing.assert_allclose(newpolar.cl, cl_3d, atol=1e-3)
np.testing.assert_allclose(newpolar.cd, cd_3d, atol=1e-3)
np.testing.assert_allclose(cm_grid, cm_test, atol=1e-3)
def test_stall1_w_airfoil(self):
R = 2.4
r = 0.25 * R
chord = 0.18
Omega = 200 * pi / 30
Uinf = 10.0
tsr = Omega * R / Uinf
af = Airfoil([self.polar])
newaf = af.correction3D(r / R,
chord / r,
tsr,
alpha_max_corr=30,
alpha_linear_min=-4,
alpha_linear_max=4)
newpolar = newaf.polars[0]
cl_3d = [
-0.8466, -0.7523, -0.6420, -0.5342, -0.4302, -0.3284, -0.2276,
-0.1303, -0.0404, 0.0618, 0.2191, 0.3321, 0.4336, 0.5501, 0.6755,
0.7363, 0.8101, 0.8973, 0.9810, 1.0640, 1.1450, 1.2098, 1.2682,
1.3281, 1.3731, 1.3088, 1.3159, 1.3534, 1.4010, 1.4515, 1.9140,
1.8857, 1.6451
]
cd_3d = [
0.0399, 0.0334, 0.0316, 0.0293, 0.0269, 0.0254, 0.0246, 0.0246,
0.0246, 0.0252, 0.0249, 0.0200, 0.0167, 0.0157, 0.0174, 0.0183,
0.0212, 0.0255, 0.0303, 0.0367, 0.0465, 0.0615, 0.0800, 0.1047,
0.1301, 0.1695, 0.2047, 0.2384, 0.2728, 0.3081, 0.8097, 1.2625,
1.6280
]
# test equality
np.testing.assert_allclose(newpolar.cl, cl_3d, atol=1e-3)
np.testing.assert_allclose(newpolar.cd, cd_3d, atol=1e-3)
def generate_af(self):
af_type = self.airfoil_parameterization_type
af_parameters = self.airfoil_parameters
if af_type == 'CST':
n = len(self.airfoil_parameters[0])
af = [0]*n
else:
n = len(self.airfoil_parameters)
af = [0]*n
r_over_R = 0.5
chord_over_r = 0.15
tsr = 7.55
cd_max = 1.5
for i in range(n):
x = []
y = []
if af_type == 'Coordinates':
try:
f = open(af_parameters[i],'r')
except:
print 'There was an error opening the airfoil file %s'%(af_parameters[i])
sys.exit(1)
for line in f:
try:
x.append(float(string.split(line)[0]))
y.append(float(string.split(line)[1]))
except:
pass
elif af_type == 'NACA':
if len(str(int(af_parameters[i]))) == 4:
pts = naca4(str(int(af_parameters[i])), 60)
elif len(str(int(af_parameters[i] == 5))):
pts = naca5(str(int(af_parameters[i])), 60)
else:
'Please input only NACA 4 or 5 series'
for j in range(len(pts)):
x.append(pts[j][0])
y.append(pts[j][1])
elif af_type == 'CST':
n = len(af_parameters)/2
wu = np.zeros(n)
wl = np.zeros(n)
for j in range(n):
wu[j] = af_parameters[j][i]
wl[j] = af_parameters[j + n][i]
# wu, wl = np.split(af_parameters[i], 2)
w1 = np.average(wl)
w2 = np.average(wu)
if w1 < w2:
pass
else:
higher = wl
lower = wu
wl = lower
wu = higher
N = 120
dz = 0.
# Populate x coordinates
x = np.ones((N, 1))
zeta = np.zeros((N, 1))
for z in range(0, N):
zeta[z] = 2 * pi / N * z
if z == N - 1:
zeta[z] = 2 * pi
x[z] = 0.5*(cos(zeta[z])+1)
# N1 and N2 parameters (N1 = 0.5 and N2 = 1 for airfoil shape)
N1 = 0.5
N2 = 1
try:
zerind = np.where(x == 0) # Used to separate upper and lower surfaces
zerind = zerind[0][0]
except:
zerind = N/2
xl = np.zeros(zerind)
xu = np.zeros(N-zerind)
for z in range(len(xl)):
xl[z] = np.real(x[z]) # Lower surface x-coordinates
for z in range(len(xu)):
xu[z] = np.real(x[z + zerind]) # Upper surface x-coordinates
yl = self.__ClassShape(wl, xl, N1, N2, -dz) # Call ClassShape function to determine lower surface y-coordinates
yu = self.__ClassShape(wu, xu, N1, N2, dz) # Call ClassShape function to determine upper surface y-coordinates
y = np.concatenate([yl, yu]) # Combine upper and lower y coordinates
y = y[::-1]
# coord_split = [xl, yl, xu, yu] # Combine x and y into single output
# coord = [x, y]
x1 = np.zeros(len(x))
for k in range(len(x)):
x1[k] = x[k][0]
x = x1
else:
print 'Error. Airfoil parameterization type not specified. Please choose Coordinates, NACA, or CST.'
if i < 3:
Re1 = [1e6]
af[0] = CCAirfoil([-180, 0, 180], Re1, [0, 0, 0], [0.5, 0.5, 0.5])
af[1] = CCAirfoil([-180, 0, 180], Re1, [0, 0, 0], [0.5, 0.5, 0.5])
af[2] = CCAirfoil([-180, 0, 180], Re1, [0, 0, 0], [0.35, 0.35, 0.35])
else:
coordinate_points = [x, y]
Re = 1e6
alphas = np.linspace(-20, 20, 80)
airfoil = pyXLIGHT.xfoilAnalysis(coordinate_points)
airfoil.re = Re
airfoil.mach = 0.03
airfoil.iter = 1000
cl = np.zeros(len(alphas))
cd = np.zeros(len(alphas))
cm = np.zeros(len(alphas))
for j in range(len(alphas)):
angle = alphas[j]
cl[j], cd[j], cm[j], lexitflag = airfoil.solveAlpha(angle)
# print cl[j], cd[j], angle
p1 = Polar(Re, alphas, cl, cd, cm)
af_p = Airfoil([p1])
af3D = af_p.correction3D(r_over_R, chord_over_r, tsr)
af_extrap1 = af3D.extrapolate(cd_max)
alpha_ext, Re_ext, cl_ext, cd_ext, cm_ext = af_extrap1.createDataGrid()
af[i] = CCAirfoil(alpha_ext, Re_ext, cl_ext, cd_ext)
return af
airfoil1 = Airfoil.initFromAerodynFile("DU21_A17.dat")
airfoil2 = Airfoil.initFromAerodynFile("DU25_A17.dat")
# blend the two airfoils
airfoil_blend = airfoil1.blend(airfoil2, 0.3)
# 3 ---------
# 4 ---------
r_over_R = 0.5
chord_over_r = 0.15
tsr = 5.0
# 3D stall correction
af3D_ex1 = af.correction3D(r_over_R, chord_over_r, tsr)
# a second example using the optional inputs
alpha_max_corr = 25 # apply full rotational correction only up to this angle of attack
alpha_linear_min = -3 # angle of attack to start evaluating slope of linear region
alpha_linear_max = 7 # angle of attack to stop evaluating slope of linear region
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,
)
def test_stall1_w_airfoil(self):
R = 2.4
r = 0.25 * R
chord = 0.18
Omega = 200 * pi / 30
Uinf = 10.0
tsr = Omega * R / Uinf
af = Airfoil([self.polar])
newaf = af.correction3D(r / R, chord / r, tsr, alpha_max_corr=30, alpha_linear_min=-4, alpha_linear_max=4)
_, _, cl_grid, cd_grid, cm_grid = newaf.createDataGrid()
newpolar = newaf.polars[0]
cl_3d = [
-0.8466,
-0.7523,
-0.6420,
-0.5342,
-0.4302,
-0.3284,
-0.2276,
-0.1303,
-0.0404,
0.0618,
0.2191,
0.3321,
0.4336,
0.5501,
0.6755,
0.7363,
0.8101,
0.8973,
0.9810,
1.0640,
1.1450,
1.2098,
1.2682,
1.3281,
1.3731,
1.3088,
1.3159,
1.3534,
1.4010,
1.4515,
1.9140,
1.8857,
1.6451,
]
cd_3d = [
0.0399,
0.0334,
0.0316,
0.0293,
0.0269,
0.0254,
0.0246,
0.0246,
0.0246,
0.0252,
0.0249,
0.0200,
0.0167,
0.0157,
0.0174,
0.0183,
0.0212,
0.0255,
0.0303,
0.0367,
0.0465,
0.0615,
0.0800,
0.1047,
0.1301,
0.1695,
0.2047,
0.2384,
0.2728,
0.3081,
0.8097,
1.2625,
1.6280,
]
cm_test = [
[-0.0037],
[-0.0044],
[-0.0051],
[0.0018],
[-0.0216],
[-0.0282],
[-0.0346],
[-0.0405],
[-0.0455],
[-0.0507],
[-0.0404],
[-0.0321],
[-0.0281],
[-0.0284],
[-0.0322],
[-0.0361],
[-0.0363],
[-0.0393],
[-0.0398],
[-0.0983],
[-0.1242],
[-0.1155],
[-0.1068],
[-0.0981],
[-0.0894],
[-0.0807],
[-0.072],
[-0.0633],
[-0.054],
[-0.045],
[-0.036],
[-0.22],
[-0.13],
]
# test equality
np.testing.assert_allclose(newpolar.cl, cl_3d, atol=1e-3)
np.testing.assert_allclose(newpolar.cd, cd_3d, atol=1e-3)
np.testing.assert_allclose(cm_grid, cm_test, atol=1e-3)
airfoil1 = Airfoil.initFromAerodynFile('DU21_A17.dat')
airfoil2 = Airfoil.initFromAerodynFile('DU25_A17.dat')
# blend the two airfoils
airfoil_blend = airfoil1.blend(airfoil2, 0.3)
# 3 ---------
# 4 ---------
r_over_R = 0.5
chord_over_r = 0.15
tsr = 5.0
# 3D stall correction
af3D_ex1 = af.correction3D(r_over_R, chord_over_r, tsr)
# a second example using the optional inputs
alpha_max_corr = 25 # apply full rotational correction only up to this angle of attack
alpha_linear_min = -3 # angle of attack to start evaluating slope of linear region
alpha_linear_max = 7 # angle of attack to stop evaluating slope of linear region
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 ---------
