def TurbofanNacelle(EngineSection,
Chord,
CentreLocation=[0, 0, 0],
ScarfAngle=3,
HighlightRadius=1.45,
MeanNacelleLength=5.67):
# The defaults yield a nacelle similar to that of an RR Trent 1000 / GEnx
HighlightDepth = 0.12 * MeanNacelleLength
SectionNo = 100
# Draw the nacelle with the centre of the intake highlight circle in 0,0,0
rs.EnableRedraw(False)
Highlight = rs.AddCircle3Pt((0, 0, HighlightRadius),
(0, -HighlightRadius, 0),
(0, 0, -HighlightRadius))
HighlightCutterCircle = rs.AddCircle3Pt((0, 0, HighlightRadius * 1.5),
(0, -HighlightRadius * 1.5, 0),
(0, 0, -HighlightRadius * 1.5))
# Fan disk for CFD boundary conditions
FanCircle = rs.CopyObject(Highlight, (MeanNacelleLength * 0.25, 0, 0))
FanDisk = rs.AddPlanarSrf(FanCircle)
# Aft outflow for CFD boundary conditions
BypassCircle = rs.CopyObject(Highlight, (MeanNacelleLength * 0.85, 0, 0))
BypassDisk = rs.AddPlanarSrf(BypassCircle)
rs.DeleteObjects([FanCircle, BypassCircle])
# Outflow cone
TailConeBasePoint = [MeanNacelleLength * 0.84, 0, 0]
TailConeApex = [MeanNacelleLength * 1.35, 0, 0]
TailConeRadius = HighlightRadius * 0.782
TailCone = rs.AddCone(TailConeBasePoint, TailConeApex, TailConeRadius)
# Spinner cone
SpinnerConeBasePoint = [MeanNacelleLength * 0.26, 0, 0]
SpinnerConeApex = [MeanNacelleLength * 0.08, 0, 0]
SpinnerConeRadius = MeanNacelleLength * 0.09
Spinner = rs.AddCone(SpinnerConeBasePoint, SpinnerConeApex,
SpinnerConeRadius)
# Tilt the intake
RotVec = rs.VectorCreate((0, 0, 0), (0, 1, 0))
Highlight = rs.RotateObject(Highlight, (0, 0, 0), ScarfAngle, axis=RotVec)
# Set up the disk for separating the intake lip later
HighlightCutterCircle = rs.RotateObject(HighlightCutterCircle, (0, 0, 0),
ScarfAngle,
axis=RotVec)
HighlightCutterDisk = rs.AddPlanarSrf(HighlightCutterCircle)
rs.DeleteObject(HighlightCutterCircle)
rs.MoveObject(HighlightCutterDisk, (HighlightDepth, 0, 0))
# Build the actual airfoil sections to define the nacelle
HighlightPointVector = rs.DivideCurve(Highlight, SectionNo)
Sections = []
TailPoints = []
Rotation = 0
Twist = 0
AirfoilSeligName = 'goe613'
SmoothingPasses = 1
for HighlightPoint in HighlightPointVector:
ChordLength = MeanNacelleLength - HighlightPoint.X
Af = primitives.Airfoil(HighlightPoint, ChordLength, Rotation, Twist,
airconics_setup.SeligPath)
AfCurve, Chrd = primitives.Airfoil.AddAirfoilFromSeligFile(
Af, AirfoilSeligName, SmoothingPasses)
rs.DeleteObject(Chrd)
P = rs.CurveEndPoint(AfCurve)
list.append(TailPoints, P)
AfCurve = act.AddTEtoOpenAirfoil(AfCurve)
list.append(Sections, AfCurve)
Rotation = Rotation + 360.0 / SectionNo
list.append(TailPoints, TailPoints[0])
# Build the actual nacelle OML surface
EndCircle = rs.AddInterpCurve(TailPoints)
Nacelle = rs.AddSweep2([Highlight, EndCircle], Sections, closed=True)
# Separate the lip
Cowling, HighlightSection = rs.SplitBrep(Nacelle, HighlightCutterDisk,
True)
# Now build the pylon between the engine and the specified chord on the wing
CP1 = [
MeanNacelleLength * 0.26 + CentreLocation[0], CentreLocation[1],
CentreLocation[2] + HighlightRadius * 0.1
]
CP2 = [
MeanNacelleLength * 0.4 + CentreLocation[0], CentreLocation[1],
HighlightRadius * 1.45 + CentreLocation[2]
]
CP3 = rs.CurveEndPoint(Chord)
rs.ReverseCurve(Chord)
CP4 = rs.CurveEndPoint(Chord)
# Move the engine into its actual place on the wing
rs.MoveObjects(
[HighlightSection, Cowling, FanDisk, BypassDisk, TailCone, Spinner],
CentreLocation)
# Pylon wireframe
PylonTop = rs.AddInterpCurve([CP1, CP2, CP3, CP4])
PylonAf = primitives.Airfoil(CP1, MeanNacelleLength * 1.35, 90, 0,
airconics_setup.SeligPath)
PylonAfCurve, PylonChord = primitives.Airfoil.AddNACA4(
PylonAf, 0, 0, 12, 3)
LowerTE = rs.CurveEndPoint(PylonChord)
PylonTE = rs.AddLine(LowerTE, CP4)
# Create the actual pylon surface
PylonLeft = rs.AddNetworkSrf([PylonTop, PylonAfCurve, PylonTE])
rs.MoveObject(PylonLeft, (0, -CentreLocation[1], 0))
PylonRight = act.MirrorObjectXZ(PylonLeft)
rs.MoveObject(PylonLeft, (0, CentreLocation[1], 0))
rs.MoveObject(PylonRight, (0, CentreLocation[1], 0))
PylonAfCurve = act.AddTEtoOpenAirfoil(PylonAfCurve)
PylonAfSrf = rs.AddPlanarSrf(PylonAfCurve)
# Assigning basic surface properties
act.AssignMaterial(Cowling, "ShinyBABlueMetal")
act.AssignMaterial(HighlightSection, "UnpaintedMetal")
act.AssignMaterial(TailCone, "UnpaintedMetal")
act.AssignMaterial(FanDisk, "FanDisk")
act.AssignMaterial(Spinner, "ShinyBlack")
act.AssignMaterial(BypassDisk, "FanDisk")
act.AssignMaterial(PylonLeft, "White_composite_external")
act.AssignMaterial(PylonRight, "White_composite_external")
# Clean-up
rs.DeleteObject(HighlightCutterDisk)
rs.DeleteObjects(Sections)
rs.DeleteObject(EndCircle)
rs.DeleteObject(Highlight)
rs.DeleteObjects([PylonTop, PylonAfCurve, PylonChord, PylonTE])
rs.Redraw()
TFEngine = [
Cowling, HighlightSection, TailCone, FanDisk, Spinner, BypassDisk
]
TFPylon = [PylonLeft, PylonRight, PylonAfSrf]
return TFEngine, TFPylon
def _BuildLS(self, ChordFactor, ScaleFactor):
# Generates a tentative lifting surface, given the general, nondimensio-
# nal parameters of the object (variations of chord length, dihedral, etc.)
# and the two scaling factors.
LEPoints = self._GenerateLeadingEdge()
Sections = []
ProjectedSections = []
TEPoints_u = []
TEPoints_l = []
for i, LEP in enumerate(LEPoints):
Eps = float(i)/self.SegmentNo
Airfoil, Chrd = self.AirfoilFunct(Eps, LEP, self.ChordFunct, ChordFactor, self.DihedralFunct, self.TwistFunct)
list.append(Sections, Airfoil)
Pr = rs.ProjectCurveToSurface(Chrd,self.XoY_Plane,self.ProjVectorZ)
list.append(ProjectedSections, Pr)
list.append(TEPoints_l, rs.CurveEndPoint(Airfoil))
list.append(TEPoints_u, rs.CurveStartPoint(Airfoil))
rs.DeleteObjects(Chrd)
LS = rs.AddLoftSrf(Sections,loft_type=self.LooseSurf)
if LS==None:
# Failed to fit loft surface. Try another fitting algorithm
TECurve_u = rs.AddInterpCurve(TEPoints_u)
TECurve_l = rs.AddInterpCurve(TEPoints_l)
rails = []
list.append(rails, TECurve_u)
list.append(rails, TECurve_l)
# Are the first and last curves identical?
# AddSweep fails if they are, so if that is the case, one is skipped
CDev = rs.CurveDeviation(Sections[0],Sections[-1])
if CDev==None:
shapes = Sections
LS = rs.AddSweep2(rails, shapes, False)
else:
shapes = Sections[:-1]
LS = rs.AddSweep2(rails, shapes, True)
rs.DeleteObjects(rails)
rs.DeleteObjects([TECurve_u, TECurve_l])
WingTip = None
if self.TipRequired:
TipCurve = Sections[-1]
TipCurve = act.AddTEtoOpenAirfoil(TipCurve)
WingTip = rs.AddPlanarSrf(TipCurve)
rs.DeleteObject(TipCurve)
# Calculate projected area
# In some cases the projected sections cannot all be lofted in one go
# (it happens when parts of the wing fold back onto themselves), so
# we loft them section by section and we compute the area as a sum.
LSP_area = 0
# Attempt to compute a projected area
try:
for i, LEP in enumerate(ProjectedSections):
if i < len(ProjectedSections)-1:
LSPsegment = rs.AddLoftSrf(ProjectedSections[i:i+2])
SA = rs.SurfaceArea(LSPsegment)
rs.DeleteObject(LSPsegment)
LSP_area = LSP_area + SA[0]
except:
print "Failed to compute projected area. Using half of surface area instead."
LS_area = rs.SurfaceArea(LS)
LSP_area = 0.5*LS_area[0]
BB = rs.BoundingBox(LS)
if BB:
ActualSemiSpan = BB[2].Y - BB[0].Y
else:
ActualSemiSpan = 0.0
# Garbage collection
rs.DeleteObjects(Sections)
try:
rs.DeleteObjects(ProjectedSections)
except:
print "Cleanup: no projected sections to delete"
rs.DeleteObjects(LEPoints)
# Scaling
Origin = rs.AddPoint([0,0,0])
ScaleXYZ = (ScaleFactor, ScaleFactor, ScaleFactor)
LS = rs.ScaleObject(LS, Origin, ScaleXYZ)
if self.TipRequired and WingTip:
WingTip = rs.ScaleObject(WingTip, Origin, ScaleXYZ)
rs.DeleteObject(Origin)
ActualSemiSpan = ActualSemiSpan*ScaleFactor
LSP_area = LSP_area*ScaleFactor**2.0
RootChord = (self.ChordFunct(0)*ChordFactor)*ScaleFactor
AR = ((2.0*ActualSemiSpan)**2.0)/(2*LSP_area)
return LS, ActualSemiSpan, LSP_area, RootChord, AR, WingTip
