def total_dict(angular_velocity):
torque_sum = 0
w = angular_velocity
for key, value in dfdict.items():
value["blade_velocity"] = value['r_position'] * w
value["relative_velocity"] = round(
math.sqrt(value["blade_velocity"]**2 + value["wind_velocity"]**2),
2)
value["arctan"] = math.degrees(
math.atan2(value["wind_velocity"], value["blade_velocity"]))
aoa = round(value["arctan"] - value["pitch_angle"], 1)
value["angle_of_attack"] = aoa
re_n = round(value["relative_velocity"] * value["chord_length"] /
0.00001511)
value["Reynolds_number"] = re_n
xf = XFoil()
if key < 13:
xf.airfoil = naca6409
else:
xf.airfoil = naca2412
xf.Re = round(re_n / 100) * 100
xf.max_iter = 200
xf.n_crit = 9.00
xf.xtr = [1.00, 1.00]
xf.M = 0
c_l, c_d, c_m, c_p = xf.a(aoa)
force_reference = 0.5 * density * value["relative_velocity"]**2
if math.isnan(c_l):
pass
else:
value["Cl"] = c_l
value["Cd"] = c_d
value["Cm"] = c_m
value["Cp"] = c_p
lift = c_l * force_reference * 0.0125 * value['chord_length']
drag = c_d * force_reference * 0.0125 * value['chord_length']
value["lift"] = lift
value["drag"] = drag
# value["torque"] = value["r_position"] * lift * math.sin(math.radians(value["pitch_angle"]))
torque = value["r_position"] * (
lift * math.sin(math.radians(value["pitch_angle"])) -
drag * math.cos(math.radians(value["pitch_angle"])))
value["torque"] = torque
torque_sum += torque
xf.reset_bls()
# detailed_df = pd.DataFrame.from_dict(dfdict, orient="index")
# print(detailed_df)
print(torque_sum, angular_velocity)
return dfdict, torque_sum
def feature_xfoil(cst_u,
cst_l,
t,
Minf: float,
Re,
AoA,
n_crit=0.1,
fname='feature-xfoil.txt'):
'''
Evaluate by xfoil and extract features.
Inputs:
---
cst-u, cst-l: list of upper/lower CST coefficients of the airfoil. \n
t: airfoil thickness or None \n
Minf: free stream Mach number for wall Mach number calculation \n
Re, AoA (deg): flight condition (s), float or list, for Xfoil \n
n_crit: critical amplification ratio for transition in xfoil \n
fname: output file name. If None, then no output \n
### Dependencies: cst-modeling3d, xfoil
'''
from cst_modeling.foil import cst_foil
from xfoil import XFoil
from xfoil.model import Airfoil
#TODO: Build foil
#! 201 is the maximum amount of points that xfoil can handle
#! tail = 0.001 is to avoid point overlap
xx, yu, yl, t0, R0 = cst_foil(201, cst_u, cst_l, x=None, t=t, tail=0.001)
#! xfoil do not support leading edge of (0,0) on both upper and lower surface
x = np.array(list(reversed(xx[1:])) + xx[1:])
y = np.array(list(reversed(yu[1:])) + yl[1:])
foil = Airfoil(x, y)
#TODO: Xfoil
xf = XFoil()
xf.print = False
xf.airfoil = foil
xf.max_iter = 40
#* Transition by power law
xf.n_crit = n_crit
#TODO: Xfoil calculation
if not isinstance(Re, list):
Re = [Re]
AoA = [AoA]
n = len(Re)
for i in range(n):
xf.reset_bls()
if Re[i] is not None:
xf.Re = Re[i]
cl, cd, cm, cp = xf.a(AoA[i])
x, cp = xf.get_cp_distribution()
print(xf.Re, AoA[i], cl)
#* Extract features
fF = PhysicalXfoil(Minf, AoA[i], Re[i])
fF.setdata(x, y, cp)
fF.extract_features()
#* Output
if fname is None:
continue
if i == 0:
f = open(fname, 'w')
else:
f = open(fname, 'a')
f.write('\n')
f.write('%10s %15.6f \n' % ('Minf', Minf))
f.write('%10s %15.6f \n' % ('AoA', AoA[i]))
f.write('%10s %15.6f \n' % ('Re', Re[i] / 1e6))
f.write('%10s %15.6f \n' % ('CL', cl))
f.write('%10s %15.6f \n' % ('Cd', cd))
f.write('%10s %15.6f \n' % ('Cm', cm))
f.close()
fF.output_features(fname=fname, append=True)
