Item 0917
DESIGN:
UniCopter ~ Trim, Stability & Control - Trim - Fuselage
Forces and Moments at the Fuselage:
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vF is the induced velocity at fuselage I think |
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v1 is the induced velocity at disk |
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-TP * cos(HalfV) is the vertical component of the port rotor's thrust.-TS * cos(HalfV) is the vertical component of the starboard rotor's thrust. |
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q is the dynamic pressure |
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AM is the disk area I think |
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ε MF = (vF / v1 ) *( ((TP * Cos(HalfV) + TS * Cos(HalfV)) / (4 * q * AM)) |
ε MF is the downwash angle |
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Θ is the helicopter's pitch angle |
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γ c is the climb angle |
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α F = Θ - γc - εMF |
α F is the angle of attack of fuselage |
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XF = |
-D F * cos(αF) + L F * sin(αF) |
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YF = |
S.F. F * cos(β) - D F * sin(β) |
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ZF = |
-L F * cos(αF) + L F * sin(αF) |
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MF = |
q * (M/q)F |
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NF = |
q * (N/q)F |
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RF = |
q * (R/q)F |
Lift and Drag Characteristics of Airframe: [Source ~ RWP1 p.679]
The following two equations are wild initial guesstimates for the UniCopter.
α = [L/q] * 2 + 5
α = √([D/q] - 1.5) * 6 or 7 or 8
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Last Revised: May 13, 2002