Elementary holicopter question

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    Elementary
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Discussion Overview

The discussion revolves around the behavior of a helicopter's body in relation to its main rotor when there is no tail rotor present. Participants explore the implications of torque and friction in this scenario, considering both theoretical and practical aspects of helicopter mechanics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants propose that without a tail rotor, the helicopter's body will naturally turn in the opposite direction of the main rotor due to the torque generated by the engine.
  • Others argue that the body will not rotate until it leaves the ground because of friction with the surface, suggesting that the body will spin in the same direction as the rotor once airborne.
  • A participant mentions that the rotational speed of the body will be proportional to its mass relative to the blades, indicating a relationship between mass and rotational dynamics.
  • One participant draws an analogy with a power drill to illustrate how torque can cause the entire system to rotate in the opposite direction of the intended motion.
  • Another participant expresses uncertainty and confusion about the direction of rotation, indicating a lack of consensus on the mechanics involved.

Areas of Agreement / Disagreement

Participants express differing views on whether the helicopter body will rotate in the same or opposite direction to the rotor. There is no consensus on the outcome, as multiple competing perspectives are presented.

Contextual Notes

Participants acknowledge the role of friction and energy input in the discussion, but the implications of these factors remain unresolved. The discussion does not reach a definitive conclusion regarding the mechanics of the helicopter's rotation.

zyenge
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If there's no tail rotor, Will the body of helicopter naturally turn along with the main rotor (in the same direction) or spin toward the opposite direction. Thanks! $15 bet with my friend ><
 
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zyenge said:
If there's no tail rotor, Will the body of helicopter naturally turn along with the main rotor (in the same direction) or spin toward the opposite direction. Thanks! $15 bet with my friend ><

What do you think will happen and why? We have no way to know if this is a homework problem or not. The answer is pretty easy to figure out, and even to demonstrate (without a helicopter).
 
My friend think that----
the engine will turn the helicopter blade in one direction and the body of the helicopter in the opposite direction. The body will not rotate until it has left the ground, because it has friction with the floor. Also the body will spin with a rotational speed proportional to the mass of the body to the blades.I think if there's no engine which is no energy input, he may be right. But with continuing energy input, it's not a closed balanced system, energy makes blade spin, then while blade is spinning, the body of helicopter should rotate along with the rotor (same direction).
 
zyenge said:
My friend think that----
the engine will turn the helicopter blade in one direction and the body of the helicopter in the opposite direction. The body will not rotate until it has left the ground, because it has friction with the floor. Also the body will spin with a rotational speed proportional to the mass of the body to the blades.


I think if there's no engine which is no energy input, he may be right. But with continuing energy input, it's not a closed balanced system, energy makes blade spin, then while blade is spinning, the body of helicopter should rotate along with the rotor (same direction).

Sorry buddy. Ask your friend if he has a preference of bill denominations that he'd like his reward in.:-p
 
DaveC426913 said:
Sorry buddy. Ask your friend if he has a preference of bill denominations that he'd like his reward in.:-p

Agreed.
 
I'll elaborate.

The engine's torque drives the propellor and the fuselage in opposite directions; the engine does not care which end is the fuselage and which end is the rotor, its purpose is only to rotate its axle relative to its body.


Try firing up a power drill when its bit is embedded in something. Instead of the drill bit turning clockwise, the whole drill turns counterclockwise, and might twist your arm off.
 
In the same direction of course because of friction dragging the heilo body along. I think:confused:
 

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