What dampens vibrations on a helicopter?

Rotor track and balance (RT&B) smoothes and reduces vibrations in helicopters caused by the rotor system.

What causes helicopter noise?

The researchers explained that most of the noise is generated by the helicopter’s main rotor. When the rotor spins, air pressure decreases above it and increases below it. This is what causes the helicopter to rise. Air flows around the blade to even out the pressure difference and creates a concentrated vortex.

What causes ground resonance in a helicopter?

Ground resonance is an imbalance in the rotation of a helicopter rotor when the blades become bunched up on one side of their rotational plane and cause an oscillation in phase with the frequency of the rocking of the helicopter on its landing gear.

What is Coriolis effect in helicopter?

The Coriolis effect is when the rotor blades speed up or slow down as the center of gravity moves closer or further away from the axis of rotation. As the rotor disc diameter becomes smaller, all the blades increase speed. This can be felt as an increase in rotor RPM, without corrective action by the pilot or governor.

What causes helicopter vibration?

A helicopter main rotor is capable of producing vibrations in both the vertical and lateral planes. A vertical vibration is a result of unequal lift produced by the main rotor blades. This vibration is a result of the airframe rolling with the mass effect caused by the unequal vertical lift component.

How do you stop a helicopter from vibrating?

Rotor Track and Balance to Reduce Helicopter Vibration The wear and tear they experience can cause the rotor to become unbalanced. Rotor Blade Track and Balancing helps reduce vibration caused by rotational movement.

What is aviation noise?

Aircraft noise pollution refers to noise produced by aircraft in flight that has been associated with several negative stress-mediated health effects, from sleep disorders to cardiovascular ones. Mechanical noise—rotation of the engine parts, most noticeable when fan blades reach supersonic speeds.

Why do helicopters fly low?

While airplanes need to maintain an altitude of 500 feet over land and 1,000 feet over congested areas, helicopters can fly much lower. The reason for this exemption is that helicopters can execute pinpoint emergency landings and are much more flexible compared to airplanes.

What causes vibration in helicopter?

What is resonance frequency?

Resonant frequency is the oscillation of a system at its natural or unforced resonance. Resonance occurs when a system is able to store and easily transfer energy between different storage modes, such as Kinetic energy or Potential energy as you would find with a simple pendulum.

What are the forces acting on a helicopter?

There are four forces acting on a helicopter in flight. They are lift, weight, thrust, and drag. See figure 2-1.

Why do helicopter blades lead and lag?

Due to dissymmetry of lift, flapping up and down occurs. Since angular momentum has to be conserved, the speed of blade increases/decreases during flapping up/down motion. To compensate for this blade leads front by a certain degree in the rotor plane, in advancing half and lags by a certain degree in retreating half.