Item 0914
DESIGN: UniCopter ~
Trim, Stability & Control - Trim - Rotors (Port & Starboard)|
FORM: Trim ~ Rotor |
Drawing:
Rotors:
April 25, 2004 ~
HalfV
(below) may be changed to ΛLAT or αLAT . In addition ΛLON or αLON may be used for longitudinal shaft tilt into wind.The final angle of
ΛLON and ΛHOS will probably be dependent on the load sharing between the rotors and the propeller at cruseForces and Moments from Port Rotor:
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XP = |
-HP* cos(HalfV) -TP * sin(Θ) |
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YP = |
TP * sin(HalfV - Φ) -HP* cos(HalfV - Φ) * sin(β) |
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ZP = |
-TP * cos(HalfV) * cos(Θ) |
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RP = |
0 Add cyclic offset ~ It may be part of arm length |
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MP = |
QP * sin(HalfV) Add cyclic offset ~ It may be part of arm length |
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NP = |
QP * cos(HalfV) Add cyclic offset ~ It may be part of arm length |
Forces and Moments from Starboard Rotor:
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XS = |
-HS* cos(HalfV) -TS * sin(Θ) |
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YS = |
-TS * sin(HalfV- Φ) -HS* cos(HalfV - Φ) * sin(β) |
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ZS = |
-TS * cos(HalfV) * cos(Θ) |
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RS = |
0 Add cyclic offset~ It may be part of arm length |
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MS = |
QS * sin(HalfV) Add cyclic offset ~ It may be part of arm length |
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NS = |
-QS * cos(HalfV) Add cyclic offse t~ It may be part of arm length |
Notes:
The two rotors produce about 1,232 lb-ft of total torque from the Lycoming engine, at maximum continuous power. With a mast-to-mast angle of 16º sin(8) = 0.1392. The nose up torque will therefor be 0.1394 * 1,232 = 171 lb-ft. For reference; the mast-to-mast angle of 24º on other previous intermeshing helicopters was sin(12) = 0.2079.
The length of at least one of the moment arms will be dependent on the amount of ABC.
This note probably belongs on another page.Information on:
H-force [H]
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Last Revised: April 25, 2004