def create_propeller(x,afOld):
diameter = 1.75
hubDiameter = 0.3
hubX = hubDiameter / diameter
baseAfPath = 'clark-Y.txt'
chordX = array([hubX,0.35,0.5,0.75,0.95])
pitchX = array([hubX,0.35,0.5,0.75,0.95])
thickX = array([hubX,0.35,0.5,0.75,0.95])
xnew = linspace(hubX,0.95,10)
betaSet = pitchX[3]
n1,n2,n3 = len(chordX), len(pitchX), len(thickX)
chordY = x[0:n1]
pitchY = x[n1:n1+n2]
thickY = x[n1+n2:]
method = 'spline'
chord = _interpolate(chordX,chordY,xnew,method)
pitch = _interpolate(pitchX,pitchY,xnew,method)
thick = _interpolate(thickX,thickY,xnew,method)
prop = propeller()
if afOld==None:
af = list()
for tc in thick:
afnew = Airfoil()
afnew.read_txt(baseAfPath)
afnew.analyze_geometry()
afnew.scale_thickness(tc,False)
afnew.build_aero_table(alphaSeq=[-40.0,40.0,1.0])
af.append(afnew)
prop.airfoil = af
else:
prop.airfoil = afOld
prop.name = 'MDO_project'
prop.diameter = diameter
prop.hubDiameter = hubDiameter
prop.chord = chord
prop.beta = pitch
prop.x = xnew
prop.r = xnew*diameter/2.0
prop.radius = diameter/2.0
prop.numBlades = 3.0
prop.thickness = thick
prop.numStations = len(xnew)
prop.analyze_geometry()
prop.set_beta(betaSet)
# if show:
# fig = plt.figure(1)
# ax1 = fig.add_subplot(311)
# ax1.grid(True)
# ax1.hold(True)
# ax1.plot(xnew,chord)
# ax2 = fig.add_subplot(312)
# ax2.grid(True)
# ax2.plot(xnew,pitch)
# ax3 = fig.add_subplot(313)
# ax3.grid(True)
# ax3.plot(xnew,thick)
# plt.show()
return prop
