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asynchronous13

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I am interested in calculating the centrifugal twisting moment (CTM) of a variable-pitch propeller blade. It's been a long time since I did anything with moments of inertia, so I'm looking for pointers to good info, or direct help if someone here can provide it.

Assume there is a propeller with two blades. For simplicity, each blade is a rectangular solid with length greater than width and negligible thickness. The blades spin around the main axis of rotation at the center of the propeller. In addition, the blades twist (variable pitch) about an axis that is perpendicular to the main axis of rotation, extends radially away from the main axis, and passes through the center of gravity of the propeller blade.

[ That was my attempt to describe the system. In plain english, it's a propeller with variable pitch blades. Hopefully my intention is clear even if my description is not. ]

Ignore aerodynamic forces (the centrifugal twisting moment is much greater than the aerodynamic twisting moment).

When the propeller is spinning, the CTM acts to reduce the blade pitch. In other words, when the propeller is spinning with no other applied forces, the blade pitch will go to zero degrees. For an actuator to hold a pitch angle in the blades, the actuator must be able to provide more force than CTM.

If the moment of inertia, mass, center of gravity, and RPM are known -- how does one calculate the centrifugal twisting moment?

http://www.scribd.com/doc/45224522/292/Propeller-Twisting-Moments [Broken]

Assume there is a propeller with two blades. For simplicity, each blade is a rectangular solid with length greater than width and negligible thickness. The blades spin around the main axis of rotation at the center of the propeller. In addition, the blades twist (variable pitch) about an axis that is perpendicular to the main axis of rotation, extends radially away from the main axis, and passes through the center of gravity of the propeller blade.

[ That was my attempt to describe the system. In plain english, it's a propeller with variable pitch blades. Hopefully my intention is clear even if my description is not. ]

Ignore aerodynamic forces (the centrifugal twisting moment is much greater than the aerodynamic twisting moment).

When the propeller is spinning, the CTM acts to reduce the blade pitch. In other words, when the propeller is spinning with no other applied forces, the blade pitch will go to zero degrees. For an actuator to hold a pitch angle in the blades, the actuator must be able to provide more force than CTM.

If the moment of inertia, mass, center of gravity, and RPM are known -- how does one calculate the centrifugal twisting moment?

http://www.scribd.com/doc/45224522/292/Propeller-Twisting-Moments [Broken]

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