How Does A Helicopter Fly? - Referring To Forward Motion.

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   quicksandposted 10 years ago

   How Does A Helicopter Fly? - Referring To Forward Motion.
   
   At first glance there is nothing visible that appears to be capable of generating forward thrust in a helicopter. What are the laws of aerodynamics that govern the forward motion of a helicopter?  Is there a simple way of explaining how a helicopter moves forward?

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   duffsmomposted 10 years ago

   I believe it is the lee and lag of the chopper blades that guide it forward.

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      quicksandposted 10 years agoin reply to this

      I also thought so. The angle the top rotor makes with the fuselage gives it a forward thrust I guess. Thanks a lot for taking time off to respond!

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   biochemiposted 10 years ago

   I think the blades attached at the top of helicopter are designed in such a way that when they are being rotated they causes air to move downward (pushes downward) generating downward force. The same but opposite in direction force (upthrust) causes helicopter to move upward leaving the land.

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      ajibuluposted 10 years agoin reply to this

      Yes, the "upthrust" is suitably called "lift" in aerodynamics and upthrust in hydrodynamics.

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   ajibuluposted 10 years ago

   When the rotor moves (In the horizontal plane as visible to an observer), it does so at an angle that produce lift but the helicopter will not rise until it is unclutched.
   
   When it is unclutched, it rises (vertically up) but this does not guarantee it will move forward until the lift component (vertically up) is resolved against the weight component (vertically down) in the direction the helicopter pilot decide to move. Remember the helicopter can move in different directions in multiple planes. This is why it is suitable for very unusual tasks.
   
   The careful actions of the helicopter pilot in providing vertical up/down movements perpendicular to the theoretically horizontal earth surface without changing its coordinate is usually the first coordinated steps in the training of the pilot. He does this repeatedly until mastery.

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      quicksandposted 10 years agoin reply to this

      Thank you very much for your explanation.

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   CWanamakerposted 10 years ago

   Yes, the simple answer is that the blades are "tilted" slightly forward. If the blades are positioned to rotate perfectly horizontal, then the helicopter will either hover or rise vertically.

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      quicksandposted 10 years agoin reply to this

      Well I guess the angle the rotor makes with the fuselage, what you call the "tilt" can be adjusted to generate that forward thrust by resolving the lift horizontally. Have I got it right? ...  and thanks a lot for your response!

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      CWanamakerposted 10 years agoin reply to this

      Yes.  Basically the more forward "tilt" the blades have, the more forward thrust that can be generated. However, more thrust means that the blades would be generating less lift.

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