Introduction and Definitions
This definition is true but it is a general one. If we take into consideration which factor improves the rotor efficiency we can say that:
So as we can see the factor which inproves rotor efficiency is any horizontal air flow across the rotor and it increases the helicopter's airspeed. We will see that the induced flow plays a major role in this process.
To illustrate the point, let's take a helicopter which is hovering (Helicopter Hover) in calm wind conditions. Of course there is a given induced flow (Forces acting on an airfoil) passing at right angles through the main rotor disc.
Now if the wind would be 24 knots, a part of the induced flow would be blown parallel to the main rotor disc , therefore a reduced amount of air will pass through the rotor disc. So we can say:
→ If the induced flow is reduced, the angle of attack increases
→ If the angle of attack increases, less power is required to lift
There is a gain in height without increase in power
- Principles of helicopter flight, 2nd Edition
- FAA helicopter Flying Handbook
- Rotorcraft Flying Handbook
- Introduction to helicopter aerodynamics
- VID 514786 - Creation
DATE OF SUBMISSION
- 12:44, 23 February 2021
- This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.
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