def initializeWingCosine(self):
theta_i = np.linspace(0.5*np.pi, np.pi, self.nj+1)
y_i = -self.span*np.cos(theta_i)
dy = self.span/float(self.nj)
for j in range(self.nj):
y = y_i[j]
yNext = y_i[j+1]
eta = y / self.span
etaNext = yNext / self.span
twist = (1.0 - eta) * self.twistRoot + eta * self.twistTip
twistNext = (1.0 - etaNext) * self.twistRoot + etaNext * self.twistTip
chord = Vector3((1.0 - eta) * self.chordRoot + eta * self.chordTip, 0.0, 0.0).rotate(0.0,twist,0.0)
chordNext = Vector3((1.0 - etaNext) * self.chordRoot + etaNext * self.chordTip, 0.0, 0.0).rotate(0.0,twistNext,0.0)
pt = Vector3(tan(self.sweep) * y, y, 0.0)
ptNext = Vector3(tan(self.sweep) * yNext, yNext, 0.0)
ds = chord / float(self.ni)
dsNext = chordNext / float(self.ni)
for i in range(self.ni):
p1 = pt
p4 = ptNext
pt = pt + ds
ptNext += dsNext
p2 = pt
p3 = ptNext
self.panels.append(panel(p1,p2,p3,p4))
def initializeWing(self):
dy = self.span/float(self.nj)
y = 0.0
yNext = y + dy
for j in range(self.nj):
eta = y / self.span
etaNext = yNext / self.span
twist = (1.0 - eta) * self.twistRoot + eta * self.twistTip
twistNext = (1.0 - etaNext) * self.twistRoot + etaNext * self.twistTip
chord = Vector3((1.0 - eta) * self.chordRoot + eta * self.chordTip, 0.0, 0.0).rotate(0.0,twist,0.0)
chordNext = Vector3((1.0 - etaNext) * self.chordRoot + etaNext * self.chordTip, 0.0, 0.0).rotate(0.0,twistNext, 0.0)
pt = Vector3(tan(self.sweep) * y, y, 0.0)
ptNext = Vector3(tan(self.sweep) * yNext, yNext, 0.0)
ds = chord / float(self.ni)
dsNext = chordNext / float(self.ni)
for i in range(self.ni):
p1 = pt
p4 = ptNext
pt = pt + ds
ptNext += dsNext
p2 = pt
p3 = ptNext
self.panels.append(panel(p1,p2,p3,p4))
y += dy
yNext += dy
def computeForcesAndMoment(self): self.CL.append(0.0) self.CM.append(0.0) self.CD.append(0.0) inducedDownwashX = np.dot(self.inducedDownwash[0],self.gamma) inducedDownwashY = np.dot(self.inducedDownwash[1],self.gamma) inducedDownwashZ = np.dot(self.inducedDownwash[2],self.gamma) for index,panel in enumerate(self.panels): force = self.Ufree.crossProduct(panel.dl()) * self.rho * self.gammaij[index] distToRefrence = self.referencePoint - panel.forceActingPoint() moment = force.crossProduct(distToRefrence) downWash = Vector3(inducedDownwashX[index], inducedDownwashY[index], inducedDownwashZ[index]) self.CL[-1] += force.dot(self.liftAxis) self.CM[-1] += moment[1] self.CD[-1] -= self.rho * downWash.dot(self.liftAxis) * self.gammaij[index] * panel.dy() self.CL[-1] /= ( 0.5 * self.rho * self.Ufree.Magnitude()**2 * self.Sref) self.CD[-1] /= ( 0.5 * self.rho * self.Ufree.Magnitude()**2 * self.Sref) self.CM[-1] /= ( 0.5 * self.rho * self.Ufree.Magnitude()**2 * self.Sref * self.cavg) if len(self.alphaRange) > 1: self.CL_alpha = (self.CL[-1]-self.CL[0])/radians(self.alphaRange[-1]-self.alphaRange[0])
def __init__(self, ni=5, nj=10, chordRoot=1.0, chordTip=1.0, twistRoot=0.0, twistTip=0.0, span=5.0, sweep=30.0, Sref = 1.0, referencePoint=[0.0,0.0,0.0], wingType=1, alphaRange = [0.0]): self.size = ni * nj self.A = np.zeros((self.size,self.size)) self.rhs = np.zeros(self.size) self.inducedDownwash = [np.zeros((self.size,self.size)), np.zeros((self.size,self.size)), np.zeros((self.size,self.size))] self.nw = 1 self.panels = [] self.wakePanels = [] self.ni = ni self.nj = nj self.gamma = np.zeros(self.size) self.gammaij = np.zeros(self.size) self.liftAxis = Vector3(0.0,0.0,1.0) self.Sref = Sref self.chordRoot = chordRoot self.chordTip = chordTip self.cavg = 0.5 * (chordRoot + chordTip) self.twistRoot = twistRoot self.twistTip = twistTip self.span = span self.AR = self.span/(self.chordRoot) self.sweep = sweep * pi / 180.0 self.referencePoint = Vector3(referencePoint[0], referencePoint[1], referencePoint[2]) self.wingType = wingType self.CL = [] self.CD = [] self.CDi = [] self.e = [] self.CM = [] self.clocal = np.zeros(self.nj) self.spanLoad = [] if not hasattr(alphaRange, '__iter__'): alphaRange = (alphaRange,) self.alphaRange = alphaRange self.Ufree = Vector3(1.0,0.0,0.0) self.rho = 1.0
def updateFreeStream(self,alpha): self.Ufree = Vector3(cos(alpha * pi / 180.0), 0.0, sin(alpha * pi / 180.0)) self.liftAxis = Vector3(-sin(alpha * pi / 180.0), 0.0, cos(alpha * pi / 180.0))
def influence(self, collocationPoint, Sym=True, boundInfluence=True):
SYM = 0
u = Vector3(0.0, 0.0, 0.0)
rcut = 1.0e-12
if (Sym): SYM = 1
for sym in range(0, SYM + 1):
x = collocationPoint.x
y = collocationPoint.y
if (sym): y *= -1.0
z = collocationPoint.z
if (boundInfluence):
edges = [0, 1, 2, 3]
else:
edges = [1, 3]
for i in edges:
if (i == 0):
x1 = self.p1.x
y1 = self.p1.y
z1 = self.p1.z
x2 = self.p4.x
y2 = self.p4.y
z2 = self.p4.z
elif (i == 1):
x1 = self.p4.x
x2 = self.p3.x
y1 = self.p4.y
y2 = self.p3.y
z1 = self.p4.z
z2 = self.p3.z
elif (i == 2):
x1 = self.p3.x
x2 = self.p2.x
y1 = self.p3.y
y2 = self.p2.y
z1 = self.p3.z
z2 = self.p2.z
elif (i == 3):
x1 = self.p2.x
x2 = self.p1.x
y1 = self.p2.y
y2 = self.p1.y
z1 = self.p2.z
z2 = self.p1.z
r1r2x = (y - y1) * (z - z2) - (z - z1) * (y - y2)
r1r2y = -((x - x1) * (z - z2) - (z - z1) * (x - x2))
r1r2z = (x - x1) * (y - y2) - (y - y1) * (x - x2)
r1 = sqrt((x - x1)**2 + (y - y1)**2 + (z - z1)**2)
r2 = sqrt((x - x2)**2 + (y - y2)**2 + (z - z2)**2)
r0 = Vector3(x2 - x1, y2 - y1, z2 - z1)
r1 = sqrt((x - x1)**2 + (y - y1)**2 + (z - z1)**2)
r2 = sqrt((x - x2)**2 + (y - y2)**2 + (z - z2)**2)
r0 = Vector3(x2 - x1, y2 - y1, z2 - z1)
# //calculation of (r1 x r2)^2
square = ((r1r2x)**2 + (r1r2y)**2 + (r1r2z)**2)
if ((r1 < rcut) or (r2 < rcut) or (square < rcut)):
pass
else:
r0r1 = (x2 - x1) * (x - x1) + (y2 - y1) * (y - y1) + (
z2 - z1) * (z - z1)
r0r2 = (x2 - x1) * (x - x2) + (y2 - y1) * (y - y2) + (
z2 - z1) * (z - z2)
coef = 1.0 / (4.0 * pi * square) * (r0r1 / r1 - r0r2 / r2)
u.x += r1r2x * coef
if (sym):
u.y -= r1r2y * coef
else:
u.y += r1r2y * coef
u.z += r1r2z * coef
return u