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Path: ACPro/ACProAerodynamics
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Computes lift and drag coefficients for a vehicle using simple formulas.
You will have to call this routine for the wing, fuselage and tail
separately using different characteristic lengths. The wing and tail use
the mean chord and the fuselage uses the length.
Altitude and velocity must be the same length.
zetaTrans is a "fudge" factor to prevent the form drag from becoming
infinite at M = 1. m0 is another "fudge" factor that prevents the
skin friction from going to infinity at Mach = 0. It fits a linear
function to the skin friction curve whose value and slope match the
curve at that Mach number.
If wing area is not entered it computes lift and drag per unit area.
Type LiftAndDrag for a demo.
Since version 3 (ACT).
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Form:
y = LiftAndDrag( d, altitude, velocity, cP, alpha )
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Inputs
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d (1,1) Aircraft parameters
.length (1,1) Representative length (e.g. mean chord) (m)
.oswaldEff (1,1) Oswald efficiency factor (0.9 to 1.0)
.aspectRatio (1,1) Aspect ratio for wing (length/mean chord)
.thickness (1,1) Ratio of length to thickness
.s (1,1) Area (m^2) optional
.zetaTrans (1,1) Damping for transonic
.sweep (1,1) Sweep angle
.a0 (1,1) Lift curve slope
.alpha0 (1,1) Zero lift angle of attack
.m0 (1,1) Mach number for linear skin
friction coefficient
altitude (1,n) Altitude (m)
velocity (1,n) Velocity at altitude (m/sec)
cP (1,1) Parasitic drag coefficient
alpha (1,n:) Angle of attack (rad)
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Outputs
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y (1,1) Output data structure
.reynoldsNumber (1,n) Reynold's number
.skinFriction (1,n) Skin friction
.formDrag (1,n) Form drag
.kInduced (1,n) Drag induced due to lift
.parasiticDrag (1,n) Parasitic drag
.cD0 (1,n) Zero lift drag coefficient
.cD (1,n) Drag coefficient
.cLOpt (1,n) Optimal lift coefficient.
.cL (1,n) Lift coefficient.
.lift (1,n) Lift
.drag (1,n) Drag
.loading (1,n) Wing loading
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See also InducedDragCoeff, SkinFrictionCoeff and FormDragCoeff,
LiftCoeff, DragCoeff, AircraftDragDataStructures.
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Reference: Miller, R. "16.751 Class Notes," MIT, 1977.
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ACPro: ACProAerodynamics/DragCoeff ACPro: ACProAerodynamics/LiftCoeff Common: Atmosphere/StdAtm Common: Graphics/Plot2D Math: Trigonometry/CosD
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